To attain reduction in size of a semiconductor device having a power transistor and an SBD, a semiconductor device according to the present invention comprises a first region and a second region formed on a main surface of a semiconductor substrate; plural first conductors and plural second conductors formed in the first and second regions respectively; a first semiconductor region and a second semiconductor region formed between adjacent first conductors in the first region, the second semiconductor region lying in the first semiconductor region and having a conductivity type opposite to that of the first semiconductor region; a third semiconductor region formed between adjacent second conductors in the second region, the third semiconductor region having the same conductivity type as that of the second semiconductor region and being lower in density than the second semiconductor region; a metal formed on the semiconductor substrate in the second region, the third semiconductor region having a metal contact region for contact with the metal, the metal being electrically connected to the second semiconductor region, and a center-to-center distance between adjacent first conductors in the first region being smaller than that between adjacent second conductors in the second region.