A connector housing 45 is formed separately from a gear housing 20 and a closing and fixing member 21. The connector housing 45 includes a retainer 49, which supports an external connector 48 relative to the closing and fixing member 21, and an elastically deformable grommet 50. A retainer-side end of the grommet 50 is interposed between a flange portion of the retainer 49 and an outer surface of the closing and fixing member 21, and the connector housing 45 is secured to a connector installation opening 43. With this construction, it is possible to achieve a high degree of design freedom and to provide a motor having a drip-proof structure of a relatively simple configuration.