In a semiconductor device, in which an insulating layer is disposed on the main face of the silicon substrate, and the insulating layer includes the protruding portion that protrudes from the end face of the silicon substrate, the protruding portion has an interconnect of Cu embedded within the insulating layer. 0 mV; and a data gathering device connected to the sensors capable of measuring the voltage difference between the sensors. The sensitivity of the MUT element can be adjusted by varying the frequency of the AC bias signal supplied to the MUT element.