the latter half the electric field is concentrated around the second corner part 20 d and the density of hall current accompanying the dynamic avalanche phenomenon is recognized on the other hand in the embodiment the two peak waveforms do not appear in other words in the embodiment it can also be evaluated that the peak waveform in the latter half disappears in the embodiment it is confirmed that the electric field concentration around the second corner part 20 d is lessened and the density of hall current accompanying the dynamic avalanche phenomenon decreases conspicuously as a result in the embodiment it is understood that the reverse recovery charge amount decreases as described above the diode 1 a of the embodiment has the reverse recovery characteristics that the reverse recovery charge amount is small and the switching loss is small 1 as illustrated in fig1 the low concentration anode diffusion region 20 c of the anode region 20 is in contact with the side face of the insulating and isolating trench 8 due to this a current path using the surface recombination effect in the interface between the low concentration anode diffusion region 20 c and the insulating and isolating trench 8 is formed consequently at the time of reverse recovery a part of reverse recovery current flows in the current path formed in the interface as a result the concentration of the reverse recovery current is lessened.