To reduce a mounting area while securing a mounting strength of a semiconductor device, a power transistor includes a chip mounting portion, a semiconductor chip, a plurality of leads, and a sealing body. An outer lead portion in each of the plurality of leads includes a first portion protruding from a second side surface of the sealing body in a first direction, a second portion extending in a second direction intersecting with the first direction, and a third portion extending in a third direction intersecting with the second direction. Furthermore, a length of the third portion in the third direction of the outer lead portion is shorter than a length of the first portion in the first direction.