diff --git a/cmd/deepl-cli/main.go b/cmd/deepl-cli/main.go
index c7d7c80..9e1b6d2 100644
--- a/cmd/deepl-cli/main.go
+++ b/cmd/deepl-cli/main.go
@@ -23,7 +23,5 @@ func main() {
 	flag.Parse()
 	fmt.Printf("Translate text from %s to %s\n", sourceLang, targetLang)
 
-	if err := repl.Repl(sourceLang, targetLang); err != nil {
-		log.Fatal(err)
-	}
+	repl.Repl(sourceLang, targetLang)
 }
diff --git a/internal/repl/repl.go b/internal/repl/repl.go
index 15bcb4e..858c1df 100644
--- a/internal/repl/repl.go
+++ b/internal/repl/repl.go
@@ -3,29 +3,40 @@ package repl
 import (
 	"bufio"
 	"fmt"
-	"io"
 	"os"
+	"strings"
 
 	"github.com/candy12t/deepl-cli/api"
 )
 
 const PROMPT = ">> "
 
-func Repl(sourceLang, targetLang string) error {
+func Repl(sourceLang, targetLang string) {
 	scanner := bufio.NewScanner(os.Stdin)
 	for {
 		fmt.Printf(PROMPT)
 		if scanned := scanner.Scan(); !scanned {
-			return fmt.Errorf("can not scan")
+			return
 		}
 
 		text := scanner.Text()
-		tr, err := api.Translate(text, sourceLang, targetLang)
-		if err != nil {
-			return err
+		if validedText, err := validText(text); err != nil {
+			fmt.Println(err)
+		} else {
+			tr, err := api.Translate(validedText, sourceLang, targetLang)
+			if err != nil {
+				fmt.Println(err)
+				return
+			}
+			fmt.Println(tr.TranslatedText())
 		}
-		out := os.Stdout
-		io.WriteString(out, tr.TranslatedText())
-		io.WriteString(out, "\n")
 	}
 }
+
+func validText(text string) (string, error) {
+	validedText := strings.TrimSpace(text)
+	if len(validedText) == 0 {
+		return "", fmt.Errorf("Error: text length is 0")
+	}
+	return validedText, nil
+}
diff --git a/internal/repl/repl_test.go b/internal/repl/repl_test.go
new file mode 100644
index 0000000..cb4f46b
--- /dev/null
+++ b/internal/repl/repl_test.go
@@ -0,0 +1,26 @@
+package repl
+
+import (
+	"testing"
+)
+
+func TestVaildText(t *testing.T) {
+	tests := []struct {
+		input        string
+		expectedText string
+	}{
+		{"\thello\t", "hello"},
+		{" hello world ", "hello world"},
+		{"\t hoge fuga \t", "hoge fuga"},
+		{"\t\n", ""},
+		{"    ", ""},
+	}
+
+	for _, tt := range tests {
+		text, _ := validText(tt.input)
+
+		if tt.expectedText != text {
+			t.Fatalf("validText() got=%q, expectedText=%q", text, tt.expectedText)
+		}
+	}
+}