An automotive alternator according to the present invention includes a rotary shaft, slip rings, a brush holder, brushes, a cover, a seal member, a cooling air flow path, and a water shield. The slip rings are fixed to an end portion of the rotary shaft. The brushes are accommodated in the brush holder and so held by the brush holder as to establish sliding contacts with the slip rings to excite the automotive alternator. The cover covers the end portion of the rotary shaft, the slip rings, the brush holder, and the brushes. The seal member is interposed between the brush holder and the cover. The cooling air flow path is formed between the seal member and one of the brush holder and the cover to supply cooling air to the brushes. The water shield works to prevent water from entering into an entrance of the cooling air flow path.