A semiconductor device includes a spaced-channel IGBT and an antiparallel diode that are formed in a same semiconductor substrate. The IGBT includes a base layer and insulated gate trenches by which the base layer is divided into a body region connected to an emitter and a floating region disconnected from the emitter. The IGBT is formed in a cell region of an IGBT region, and the diode is formed in a diode region. A boundary region of the IGBT region is located between the cell region and the diode region. A spacing between adjacent gate trenches in the boundary region is less than a spacing between adjacent gate trenches between which the floating region is located in the cell region.