Provided is a brushless alternator for preventing water from penetrating further inside through a gap between a distal end portion of a spool and a concave portion of a bracket. According to the brushless alternator of the present invention, a rotor includes: a rotor main body; and a coil body (30) fixed to a rear bracket (21). The coil body (30) includes: a bobbin (32); a field coil (13); a yoke portion (10) of a second magnetic pole, the yoke portion (10) having one lateral surface being in close contact with a lateral surface of the bobbin (32) and another lateral surface being bonded to the rear bracket (21); a spool (31) provided on an inner circumferential surface of the yoke portion (10) and an inner circumferential surface of the bobbin (32); and a rubber bush (101) provided to a projecting portion (312) at a distal end of the spool (31). The rubber bush (101) is fitted into a concave portion (21a) formed at a portion of the rear bracket (21), the portion being opposed to a distal end surface of the spool (31).