To provide a capacitor fitting structure for a power conversion apparatus by which a plurality of capacitors can be appropriately cooled and the mounting density be also improved.

A plurality of capacitors 4a-4d are comprised of capacitors having an elliptic section with long and short sides respectively. The capacitors 4a-4d are respectively provided with capacitor fitting members 7a-7d having an L-shaped section, and their long-side sides are fixed to the capacitors 4a-4d. In addition, the capacitors 4a to 4d are arranged side by side so that the long sides amy be opposite to each other, and the capacitor fitting members 7a-7c are pinched tight with the long-side sides of the adjoining capacitors, so that heat from the capacitors 4a-4d may be conducted to the capacitor fitting members 7a-7d.