This capacitor includes: a capacitor element; a case made of metal and configured to house the capacitor element; and a thermosetting resin that is filled in the case. The case includes a bottom face and a side face, the side face surrounding four sides of the bottom face. The side face has formed therein a plurality of slit parts, the plurality of slit parts extending from an end, of the side face, at an opposite side to the bottom face toward the bottom face side.