ROTATING ELECTRICAL MACHINE CASE

A rotating electrical machine case (1) includes a case body (10) having a cylindrical shape surrounding a rotating electrical machine and a side wall portion (20) provided on at least one end side of the case body (10) in a rotation axis direction. The side wall portion (20) is provided with a plurality of ribs (41) to (44) extending in a radial direction when viewed from the rotation axis direction of a rotating electrical machine MOT and the plurality of ribs (41) to (44) include ribs having different circumferential widths.