An object is to assemble a housing to a mating bracket with high accuracy and to improve the reliability of a rotating electrical machine. A housing of a rotating electrical machine according to the present invention is a housing of a rotating electrical machine that accommodates a stator of the rotating electrical machine and is supported by a support member, the housing including: a first tab that forms a first through-hole through which a first screw passes; and a second tab that forms a second through-hole through which a second screw passes and forms a fitting portion that fits with a position adjustment member, wherein the first tab is formed such that a first facing surface facing the support member of the first tab is farther from the support member than a second facing surface facing the support member of the second tab.