To a power converter capable of miniaturizing a device while coping with leakage of cooling water from each unit inverter, connection line maintenance, and easy inspection of laying inspected easily, and taking heat measures against thermally sensitive goods.

An enclosure 106 stores an input transformer 105 and unit inverters 103u, 103v, 103w composed of a switching element cooled by cooling water, a rectifier, and a smoothing capacitor while stacking the unit inverters 103u, 103v, and 103w vertically by providing a partition board 2 therebetween. The partition board 2 is in a tray shape including a bank-like section 3 in an outer edge portion, has a shape larger than a projection surface when the unit inverters 103u, 103v, 103w are viewed from above, and attaches a connection line 110 between the input transformer 105 and the unit inverters 103u, 103v, 103w.