PURPOSE: To provide a compact and light-weight starting and generating apparatus for a vehicle, wherein the inertia of a rotor is small and the durability of a brush is excellent.

CONSTITUTION: In a starting and generating apparatus for vehicle, wherein a starting coil 23 and a generating coil 22 are wound around the stator core of the same armature, a rotary inner-magnet type rotor 10, which is coupled with a rotary shaft, is arranged at the inner side of the diameter of the stator core 21. A brush holder 30, which is allowed to be relatively moved with respect to the rotary inner-magnet type rotor 10 in the axial direction and rotated as a unitary body, is provided at the side of this rotary inner-magnet type rotor 10. A plurality of brushes 31 are protrudingly provided on the outer surface of the brush holder 30. A plurality of commutators 43 are arranged at the specified positions on the inner surface of a fixed commutator holder 40, which is provided so as to face the outer surface of the brush holder 30. The brushes, 31 and the commutators 43 can be brought into contact and separated by the movement of the brush holder 30 in the axial direction. Electric power is supplied to the starting coil 23 at the time of contact. This is the apparatus for starting and electric-power generation for a vehicle.