SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To provide a semiconductor device capable of reducing a channel resistance to increase an on-state current, and of operating each transistor independently and stably.SOLUTION: A semiconductor device comprises: a fin part 15 formed to protrude from a bottom part of a gate electrode groove; a gate insulating film 21 covering surfaces of the gate electrode groove and the fin part 15; a gate electrode filling in a lower part of the gate electrode groove, and formed to stride over the fin part 15 via the gate insulating film 21; a first impurity diffusion region arranged on a first lateral face; and a second impurity diffusion region arranged on a second lateral face. With respect to the gate insulating film 21, a relation between a thickness t1 of the first and second lateral faces of the gate electrode groove and a thickness t2 of an upper part 15a of the fin part 15 is t1