A power converter includes an inverter in an inverter case, and a DC/DC converter in a converter case detachably fixed to the inverter case. The inverter includes power semiconductor modules, and the DC/DC converter includes a down-converter circuit and/or a boost converter circuit. The inverter case includes first and second path-forming members thermally contacting the converter case. In the first path-forming member, the power semiconductor module is inserted into a first coolant path. In the second path-forming member, the power semiconductor module inserted into the second coolant path, which is parallel to the first coolant path. The DC/DC converter includes an inductance device, and a switching device board on which a switching device con rolling electric current in the inductance device is mounted. The inductance and switching devices are in an area of the converter case thermally contacting first and second path forming members.