A semiconductor device includes a drift layer of a first conductivity-type, having a super junction structure, including a plurality of columns of a second conductivity-type, a plane pattern of each of the columns extends along a parallel direction to the principal surface of the layer, the columns are arranged at regular intervals; a plurality of well regions of the second conductivity-type provided in a surface-side layer of the layer of the first conductivity-type; a plurality of source regions of the first conductivity-type selectively provided in the plurality of well regions; a gate insulating film provided on the principal surface; an array of gate electrodes disposed on the gate insulating film, each of the gate electrodes is provided so as to bridge the corresponding source regions in a pair of neighboring two well regions; and a temperature detection diode provided at a partial area defined in the array of the gate electrodes.