Water-drop proof structure for wiper motor apparatus

The present invention relates to a wiper motor device, in which a drive circuit portion and an output shaft are disposed adjacent to each other. A structure is provided which is capable of preventing water from coming into contact with the drive circuit portion in the event that water invades along the output shaft. A cover 11 for an accommodation casing 10 which houses the drive circuit portion includes an extension portion 11e and a cylindrical portion 11f externally fitted to the output shaft 3. The lower part of a waterproof cap 12 attached to the output shaft 3 is located around the upper part of the cylindrical portion 11f.