To provide an AC generator for vehicle, in which internal failures can be detected without adding extra signal line, and the output can be controlled efficiently based on a detected current value.

A current detector 11, integrated with a protective member 7, is provided at an output terminal 61 of a rectifier 6 built in an AC generator for vehicle. The current detector 11 detects the output current from the AC generator for vehicle flowing through the output terminal 61 and delivers detection signal to a power generation controller 8. The power generation controller 8 performs output current control for alarming abnormality, at malfunction of power generation or balancing of the charging efficiently, based on a detection signal delivered from the current detector 11.