The present invention provides a semiconductor device capable of selecting a desired circuit (step-down circuit (or step-up/step-down circuit) and step-up circuit) on the user side at low cost. A semiconductor device according to the present invention includes a diode element and a switching element (IGBT). An anode terminal of the diode element and one main electrode terminal of the switching element are adjacently arranged at a predetermined distance from each other. In addition, a cathode terminal of the diode element and the other main electrode terminal of the switching element are adjacently arranged at another predetermined distance from each other.