PURPOSE: To provide a monitor element having high detection sensitivity to damages to an insulating film due to electric charges, by electrically connecting at least one of gate electrodes of the monitor element to a diffusion layer having pn junction with a substrate and arranging the monitor element and the diffusion layer separated away from each other at a predetermined distance or more.

CONSTITUTION: At least one of gate electrodes of a monitor element composed of a transistor of an integrated circuit device having a MISFET is electrically connected to a diffusion layer 12 having pn junction with a substrate 1. The monitor element and the diffusion layer 12 are separated away from each other at a predetermined distance or more. The processing distance is equal to or greater than the distance at which damages to a gate insulating film of the monitor element start to be detected. In addition, a measurement pad connected to a source 9, a drain 8, a gate 11, a well 10 and the substrate 1 is provided so as to detect the damages to the gate insulating film by the shift amount of threshold voltage of the monitor element.