A power conversion apparatus includes: a cooling air passage defined with cooling fins of upper and lower converters and cooling fins of an inverter opposed to each other; upper and lower blowing fans provided upstream of the cooling air passage; and upper and lower sucking fans provided downstream of the cooling air passage and at positions offset from the converters. The blowing fans are provided for supplying cooling air from upstream of the cooling air passage, and the sucking fans are provided for discharging air from within a casing of the apparatus to the outside.