Abstract: Provided is a technology that can sufficiently suppress the temperature rise of a rotary electrical machine. A rotary electrical machine includes a main body part 10 including a rotator and a stator, and a casing part 20 that houses the main body part 10. The casing part 20 includes a first housing part 5 that surrounds the main body part 10 from a peripheral direction, and a second housing part 6 that houses a bearing for rotatably supporting a rotating shaft 2. The casing part 20 is formed with a cooling passage R extending from an inlet Rs for cooling medium to an outlet Re for cooling medium and not branching off in the middle. The cooling passage R includes a first cooling passage portion R1 that passes through the inside of the first housing part 5 and a second cooling passage portion R2 that passes through the inside of the second housing part 6.