A semiconductor device according to an embodiment includes a first diode portion including a first trench extending in a first direction, and a first trench electrode; a second diode portion adjacent to the first diode portion in the first direction and includes a second trench extending in the first direction, and a second trench electrode and of which the width in the first direction is greater than the width of the first diode portion in a second direction perpendicular to the first direction; and a first IGBT portion adjacent to the first diode portion in the second direction and is adjacent to the second diode portion in the first direction and includes a third trench extending in the first direction, and a first gate electrode.