To install a power converter housing apparatus so as to carry out effective air-cooling to suppress the dimensional increase and waste energy consumption of a power converter, to prevent the leakage of a secondary battery electrolyte from giving damages to surroundings, even if the installation posture of the power converter is different from a normal posture, and to avoid defects produced in a narrow cross-section part of a push-botton cover made of synthetic resin, when the cover is molded integrally.

This power converter has an air-flow path, with which a printed board 13 on which semiconductor devices 14 are mounted and reactors 12 can be totally cooled by a cooling air-flow produced by a cooling fan 16. A lead battery 2 is housed between a lower electrolyte receiver 4 and a side electrolyte receiver 5, which are assembled into an L-shape to receive a leaking electrolyte, even if a power converter is installed sideways. A push-button cover 22 covering push-button switches attached to the surface of the power converter has pushing parts 24 positioned in windows 23, provided at positions corresponding to the push-button switches and the pushing parts 24 and the circumferences of the windows 23 are connected to each other with connection legs 25. Resin casting inlets used, when the pushing parts 24, the connection legs 25, and the push-button cover 22 are integrally molded are formed in the pushing unit 24.