Cooling performance of a control circuit substrate used in a power converter is improved. A power converter of the present invention includes a power semiconductor module, a passage forming body forming a passage space, a driver circuit substrate, and a control circuit substrate, where the passage forming body forms a first opening for allowing to dispose the power semiconductor module in an opposing manner to the passage space, the driver circuit substrate is disposed at a position opposite to a surface of the passage forming body having the first opening formed thereon, the passage forming body forms a side surface part parallel to an alignment direction of the power semiconductor module and driver circuit substrate, and the control circuit substrate is disposed on the side surface via a protruding portion protruding from the side surface such that a projection of the control circuit substrate matches that of the passage space when a projection is made from a direction perpendicular to the side surface of the passage forming body.