PURPOSE: To prevent a window screen from being injured by making it possible to operate a wiper and inject a washer solution simultaneously with the single operation of a wiper switch in case of a wiper device used for the window screen mounted on the front part of a motorcycle.

CONSTITUTION: When a wiper switch 16 is turned on, a washer motor 15 and a wiper motor 7 are simutaneously started, and a washer solution discharged from a washer pump 14 is injected from a washer nozzle 30 via a tube 31 onto the surface of a window screen 3. Moreover, a transmission mechanism 8 is operated by the starting of the wiper motor 7, and respective wiper arms 4b, 5b for the window screen 3 and a head light 6 begin a reciprocating rotary motion, allowing a wiping operation to be obtained by wiper blades 4d, 5d. Here, a washer solution and rainwater, etc., entering inside a cover 2C are discharged from an opening part on the head light 6.