diff --git a/radar-service-impl/src/main/java/com/pgmmers/radar/service/impl/engine/plugin/SUBSTRING.java b/radar-service-impl/src/main/java/com/pgmmers/radar/service/impl/engine/plugin/SUBSTRING.java
index 082e29d..e25f397 100644
--- a/radar-service-impl/src/main/java/com/pgmmers/radar/service/impl/engine/plugin/SUBSTRING.java
+++ b/radar-service-impl/src/main/java/com/pgmmers/radar/service/impl/engine/plugin/SUBSTRING.java
@@ -30,7 +30,7 @@ public Object handle(PreItemVO item, Map<String, Object> jsonInfo, String[] sour
         String field = jsonInfo.get(sourceField[0]).toString();
         int start =Integer.parseInt(args[0]);
         int end = Integer.parseInt(args[1]);
-        if (field != null && field.length() > end) {
+        if (field != null && (field.length() > end || field.length() == end)) {
             return field.substring(start, end);
         } else {
             return field;