An insulated-gate semiconductor device includes: a carrier transport layer of a first conductivity-type made of a semiconductor material having a wider band gap than silicon; a lower buried region of a second conductivity-type buried in an upper portion of the carrier transport layer; a plurality of upper buried regions of the second conductivity-type dispersedly deposited on the lower buried region; an injection control region of the second conductivity-type deposited on the upper buried regions; and an insulated gate structure controlling a surface potential of the injection control region adjacent to a side wall of a trench, wherein the trench has a stripe-like shape, the lower buried region includes a first stripe provided separately from the trench, and the respective upper buried regions are provided at intervals on the first stripe.