AC generator for a vehicle

The invention is intended to simplify the structure of an AC generator having a cooling function for a vehicle, forming an annular cooling chamber device (7) with the aid of recessed portions annularly ( 4, 5) formed at least on the front holder (2) and the rear support (3), forming a rear cooling chamber (21) with the rear support (3) and the cooling cover (18), and connecting the two cooling chambers (7, 21) through a connecting hole (25).