diff --git a/infra/config/config.go b/infra/config/config.go
index c571847..56eb86b 100644
--- a/infra/config/config.go
+++ b/infra/config/config.go
@@ -1,7 +1,7 @@
 package config
 
 import (
-	"log/slog"
+	"fmt"
 	"path"
 	"runtime"
 
@@ -62,7 +62,7 @@ func NewConfig() (*Config, error) {
 
 	err := viper.ReadInConfig()
 	if err != nil {
-		slog.Error("Read config file.", "err", err)
+		fmt.Println("Read config file.", "err", err)
 		return nil, err
 	}
 
@@ -70,7 +70,7 @@ func NewConfig() (*Config, error) {
 
 	err = viper.Unmarshal(&conf)
 	if err != nil {
-		slog.Error("Unmarshal config file.", "err", err)
+		fmt.Println("Unmarshal config file.", "err", err)
 		return nil, err
 	}
 
diff --git a/infra/router/middleware/middleware.go b/infra/router/middleware/middleware.go
index 58cacef..76a9145 100644
--- a/infra/router/middleware/middleware.go
+++ b/infra/router/middleware/middleware.go
@@ -1,7 +1,7 @@
 package middleware
 
 import (
-	"log/slog"
+	"fmt"
 	"net/http"
 
 	"github.com/gin-contrib/cors"
@@ -21,7 +21,7 @@ func ErrorHandler(c *gin.Context) {
 	c.Next()
 
 	for _, err := range c.Errors {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 	}
 
 	c.JSON(http.StatusInternalServerError, "")
diff --git a/infra/router/util/validate.go b/infra/router/util/validate.go
index c790c02..aa19c18 100644
--- a/infra/router/util/validate.go
+++ b/infra/router/util/validate.go
@@ -2,7 +2,6 @@ package util
 
 import (
 	"fmt"
-	"log/slog"
 	"strconv"
 
 	"github.com/gin-gonic/gin"
@@ -12,7 +11,7 @@ func ValidateBody[T any](c *gin.Context) (*T, error) {
 	var input T
 
 	if err := c.ShouldBind(&input); err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, err
 	}
 
@@ -26,7 +25,7 @@ func ValidateQuery[T any](c *gin.Context) (*T, error) {
 	fmt.Println(values)
 
 	if err := c.ShouldBindQuery(&input); err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, err
 	}
 
@@ -38,7 +37,7 @@ func ValidateInt64Param(c *gin.Context, key string) (*int64, error) {
 	id, err := strconv.ParseInt(param, 10, 64)
 
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, err
 	}
 
diff --git a/internal/usecase/item/item_ucase.go b/internal/usecase/item/item_ucase.go
index e70ca7c..51ae436 100644
--- a/internal/usecase/item/item_ucase.go
+++ b/internal/usecase/item/item_ucase.go
@@ -1,7 +1,7 @@
 package item
 
 import (
-	"log/slog"
+	"fmt"
 
 	"github.com/team-nerd-planet/api-server/internal/entity"
 )
@@ -19,7 +19,7 @@ func NewItemUsecase(itemRepo entity.ItemRepo) ItemUsecase {
 func (iu ItemUsecase) CountViewItem(company *string, companySizes *[]entity.CompanySizeType, jobTags, skillTags *[]int64) (*int64, bool) {
 	count, err := iu.itemRepo.CountView(company, companySizes, jobTags, skillTags)
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, false
 	}
 
@@ -29,7 +29,7 @@ func (iu ItemUsecase) CountViewItem(company *string, companySizes *[]entity.Comp
 func (mu ItemUsecase) FindAllViewItem(company *string, companySizes *[]entity.CompanySizeType, jobTags, skillTags *[]int64, perPage int, page int) (*[]entity.ItemView, bool) {
 	viewItems, err := mu.itemRepo.FindAllView(company, companySizes, jobTags, skillTags, perPage, page)
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, false
 	}
 
diff --git a/internal/usecase/subscription/subscriber_ucase.go b/internal/usecase/subscription/subscriber_ucase.go
index e1c07db..54f2e59 100644
--- a/internal/usecase/subscription/subscriber_ucase.go
+++ b/internal/usecase/subscription/subscriber_ucase.go
@@ -5,7 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"html/template"
-	"log/slog"
 	"net/smtp"
 	"path"
 	"runtime"
@@ -34,7 +33,7 @@ func NewSubscriptionUsecase(
 func (su SubscriptionUsecase) ApplySubscription(subscription entity.Subscription) (*entity.Subscription, bool) {
 	id, err := su.subscriptionRepo.ExistEmail(subscription.Email)
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, false
 	}
 
@@ -50,7 +49,7 @@ func (su SubscriptionUsecase) ApplySubscription(subscription entity.Subscription
 
 	tokenStr, err := generateEmailToken(token, su.conf.Jwt.SecretKey)
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, false
 	}
 
@@ -78,7 +77,7 @@ func (su SubscriptionUsecase) Subscribe(token string) (*entity.Subscription, boo
 
 	emailToken, err = verifyEmailToken(token, su.conf.Jwt.SecretKey)
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, false
 	}
 
@@ -94,7 +93,7 @@ func (su SubscriptionUsecase) Subscribe(token string) (*entity.Subscription, boo
 	}
 
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, false
 	}
 
@@ -120,13 +119,13 @@ func sendSubscribeMail(host string, port int, userName, password, email, token s
 	configDirPath := path.Join(path.Dir(b))
 	t, err := template.ParseFiles(fmt.Sprintf("%s/template/subscription.html", configDirPath))
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return err
 	}
 
 	var body bytes.Buffer
 	if err := t.Execute(&body, data); err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return err
 	}
 
diff --git a/internal/usecase/tag/job_tag_ucase.go b/internal/usecase/tag/job_tag_ucase.go
index 3d67588..0b83d8d 100644
--- a/internal/usecase/tag/job_tag_ucase.go
+++ b/internal/usecase/tag/job_tag_ucase.go
@@ -1,7 +1,7 @@
 package tag
 
 import (
-	"log/slog"
+	"fmt"
 
 	"github.com/team-nerd-planet/api-server/internal/entity"
 )
@@ -19,7 +19,7 @@ func NewJobTagUsecase(jobTagRepo entity.JobTagRepo) JobTagUsecase {
 func (stu JobTagUsecase) FindAll() (*[]entity.JobTag, bool) {
 	jobTags, err := stu.jobTagRepo.FindAll()
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, false
 	}
 
diff --git a/internal/usecase/tag/skill_tag_ucase.go b/internal/usecase/tag/skill_tag_ucase.go
index 838e491..b8bdf9a 100644
--- a/internal/usecase/tag/skill_tag_ucase.go
+++ b/internal/usecase/tag/skill_tag_ucase.go
@@ -1,7 +1,7 @@
 package tag
 
 import (
-	"log/slog"
+	"fmt"
 
 	"github.com/team-nerd-planet/api-server/internal/entity"
 )
@@ -19,7 +19,7 @@ func NewSkillTagUsecase(skillTagRepo entity.SkillTagRepo) SkillTagUsecase {
 func (stu SkillTagUsecase) FindAll() (*[]entity.SkillTag, bool) {
 	skillTags, err := stu.skillTagRepo.FindAll()
 	if err != nil {
-		slog.Error(err.Error())
+		fmt.Println(err.Error())
 		return nil, false
 	}