Provided is an inverter 1 configured such that an electric component portion 1a is integrated with a cooling portion 1b. A switching module 20 includes a heat sink 102 joined to the lower surface of a substrate 101. The cooling portion 1b includes an electric conductive cooler 10 forming a refrigerant flow path 11. The switching module 20 is attached to the cooler 10 such that a heat radiation portion 102d of the heat sink 102 is exposed to the inside of the cooler 10. A common mode current suppression structure 21 including an insulating member is interposed between the heat sink 102 and the cooler 10 to electrically insulate the heat sink 102 and the cooler 10 from each other.