a first main electrode formed along one main surface;

a first semiconductor layer of first conductivity type electrically connected to the first main electrode;

a cyclic structure section which is formed on the first semiconductor layer and has second semiconductor layers of first conductivity type and third semiconductor layers of second conductivity type alternately and cyclically formed along the one main surface;

a fourth semiconductor layer of second conductivity type selectively formed on a part of the second and third semiconductor layers;

a fifth semiconductor layer of first conductivity type selectively formed on the fourth semiconductor layer;

a second main electrode contacted the fourth and fifth semiconductor layers;

a control electrode disposed adjacent via a first insulating film on the second, fourth and fifth semiconductor layers; and

a depletion layer blocking section which is formed outside of the cyclic structure section and prevents a depletion layer from spreading outside,

wherein the depletion layer blocking section includes a conductive layer formed via a second insulating film in a first trench formed outside of the outermost third semiconductor layer in the cyclic structure section, the depletion layer blocking section being electrically connected to the first main electrode or being in a floating state.