A rotating electrical machine having holding surfaces on a pair of housings which firmly holds a stator core made of a core stack. The holding surfaces have a small-diameter first annular surface and a large-diameter second annular surface arranged at different locations in the axial direction. The surfaces in contact with inner and outer circumferential regions of a yoke hold the core. Two contacts between the housing and core are in different locations on a radial and axial direction. An outer peripheral side of the yoke where plate thickness is smaller and an inner peripheral side where plate thickness is larger are pressed individually in the axial direction. A firm holding feature suitable for configuration of the yoke is ensured to setting a difference in level between the contacts Eliminating problems about gaps created between layers of the core stack without any changes to the structure of the core stack.