A rotary electrical device includes a rotor having a substantially hollow cylindrical shape or a substantially solid cylindrical; and a stator having a substantially annular shape and disposed to surround a rotation axis of the rotor. The stator includes a winding that is wound around the rotation axis, and a stator core that surrounds the winding and is constituted by a magnetic powder core. The stator core includes a plurality of cores facing each other with the winding interposed therebetween in an axial direction of the stator. One core of the plurality of cores includes a yoke that is in contact with or in proximity to one other core of the plurality of cores, and one or more claw magnetic poles that protrude from the yoke toward the rotor in the radial direction. The one or more claw magnetic poles of the one core are alternately arranged with claw magnetic poles of the one other core, with which or to which the yoke is in contact or in proximity, in a circumferential direction of the stator. The yoke has at least one yoke surface that is substantially parallel to the axial direction, and the yoke surface of the yoke is in contact with or in proximity to the one other core.