diff --git a/ec2id.go b/ec2id.go
index 44dbf14..0695ecb 100644
--- a/ec2id.go
+++ b/ec2id.go
@@ -30,16 +30,17 @@ func NewAwsClient() (EC2DescribeInstancesAPI, error){
 }
 
 func Ec2id(name string, client EC2DescribeInstancesAPI) (string, error) {
-	var params *ec2.DescribeInstancesInput = nil
-	if len(name) != 0 {
-		params = &ec2.DescribeInstancesInput{
-			Filters: []types.Filter{
-				{
-					Name:   aws.String("tag:Name"),
-					Values: []string{name},
-				},
+	var params = &ec2.DescribeInstancesInput{
+		Filters: []types.Filter{
+			{
+				Name:   aws.String("tag:Name"),
+				Values: []string{name},
 			},
-		}
+			{
+				Name: aws.String("instance-state-name"),
+				Values: []string{"running"},
+			},
+		},
 	}
 
 	result, err := GetInstances(context.TODO(), client, params)
@@ -56,9 +57,6 @@ func Ec2id(name string, client EC2DescribeInstancesAPI) (string, error) {
 	var filteredInstance = result.Reservations[0].Instances[0]
 	for _, v := range result.Reservations {
 		for _, instance := range v.Instances {
-			if string(filteredInstance.State.Name) == "running" && string(instance.State.Name) != "running" {
-				continue
-			}
 			if filteredInstance.LaunchTime.After(*instance.LaunchTime) {
 				continue
 			}
diff --git a/ec2id_test.go b/ec2id_test.go
index 655d6c0..1bc120f 100644
--- a/ec2id_test.go
+++ b/ec2id_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/golang/mock/gomock"
 	"github.com/aws/aws-sdk-go-v2/aws"
@@ -21,11 +22,85 @@ func TestEc2id(t *testing.T) {
 					Name: aws.String("tag:Name"),
 					Values: []string{"noexist"},
 				},
+				{
+					Name: aws.String("instance-state-name"),
+					Values: []string{"running"},
+				},
 			},
 		}).
 		Return(&ec2.DescribeInstancesOutput{}, nil).
 		AnyTimes()
 
+	mockClient.EXPECT().
+		DescribeInstances(context.TODO(), &ec2.DescribeInstancesInput{
+			Filters: []types.Filter{
+				{
+					Name: aws.String("tag:Name"),
+					Values: []string{""},
+				},
+				{
+					Name: aws.String("instance-state-name"),
+					Values: []string{"running"},
+				},
+			},
+		}).
+		Return(&ec2.DescribeInstancesOutput{
+			Reservations: []types.Reservation {
+				{
+					Instances: []types.Instance {
+						{
+							InstanceId: aws.String("i-0123456789abcdef0"),
+							LaunchTime: aws.Time(time.Date(2023, 1, 5, 12, 0, 0, 0, time.UTC)),
+						},
+						{
+							InstanceId: aws.String("i-0123456789abcdef1"),
+							LaunchTime: aws.Time(time.Date(2023, 1, 5, 12, 0, 0, 1, time.UTC)),
+						},
+						{
+							InstanceId: aws.String("i-0123456789abcdef2"),
+							LaunchTime: aws.Time(time.Date(2023, 1, 5, 12, 0, 0, 2, time.UTC)),
+						},
+					},
+				},
+				{
+					Instances: []types.Instance {
+						{
+							InstanceId: aws.String("i-00000000000abcdef"),
+							LaunchTime: aws.Time(time.Date(2023, 1, 4, 12, 0, 0, 0, time.UTC)),
+						},
+					},
+				},
+			},
+		}, nil).
+		AnyTimes()
+
+	mockClient.EXPECT().
+		DescribeInstances(context.TODO(), &ec2.DescribeInstancesInput{
+			Filters: []types.Filter{
+				{
+					Name: aws.String("tag:Name"),
+					Values: []string{"test"},
+				},
+				{
+					Name: aws.String("instance-state-name"),
+					Values: []string{"running"},
+				},
+			},
+		}).
+		Return(&ec2.DescribeInstancesOutput{
+			Reservations: []types.Reservation {
+				{
+					Instances: []types.Instance {
+						{
+							InstanceId: aws.String("i-00000000000abcdef"),
+							LaunchTime: aws.Time(time.Date(2023, 1, 4, 12, 0, 0, 0, time.UTC)),
+						},
+					},
+				},
+			},
+		}, nil).
+		AnyTimes()
+
 	cases := []struct {
 		name string
 		client EC2DescribeInstancesAPI
@@ -42,6 +117,22 @@ func TestEc2id(t *testing.T) {
 			wantErr: false,
 			expectErr: "",
 		},
+		{
+			name: "return latest instance-id by no input",
+			client: mockClient,
+			instanceName: "",
+			expect: "i-0123456789abcdef2",
+			wantErr: false,
+			expectErr: "",
+		},
+		{
+			name: "return instance-id",
+			client: mockClient,
+			instanceName: "test",
+			expect: "i-00000000000abcdef",
+			wantErr: false,
+			expectErr: "",
+		},
 	}
 
 	for _, tt := range cases {