The present invention provides a sensor element including two diode elements connected in series to each other, and a capacitive element having one end connected to a junction point between the two diode elements. Each of the diode elements includes a semiconductor layer having a p-type semiconductor region and an n-type semiconductor region facing each other in an in-plane direction, an anode electrode connected to the p-type semiconductor region, a cathode electrode connected to the n-type semiconductor region, a gate insulting film adjoining the semiconductor layer in a stacking direction, and a gate electrode facing the semiconductor layer with the gate insulating film in between.