Provided is a test element group (TEG) pattern for detecting a void in a device isolation layer. The TEG pattern includes active regions which are parallel to each other and extend in a first direction, a device isolation layer that separates the active regions, a first contact that is formed across the device isolation layer and a first one of the active regions that contacts a surface of the device isolation layer, and a second contact that is formed across the device isolation layer and a second one of the active regions that contacts another surface of the device isolation layer.