PURPOSE: To eliminate wiper containing work through driver by deciding whether the wiper blade should be contained or not with reference to raining condition and containing the wiper blade automatically upon interruption of rain.

CONSTITUTION: A rain detector is employing a light emission element 2 and a photoreceptor element secured to the inner face of front glass 3 as single detector where they are arranged such that the light beam emitted from light emission element 2 is fully reflected at least one time in the glass 3 and reaches to the photoreceptor element 1. A plurality of said detectors 1AW1N are arranged on the front glass to provide a signal through multiplexer 8, amplifier 9, filter 10 and amplifier to A/D converter. Rainfall is decided by a microcomputer 13 and upon decision of complete interruption of rainfall, wiper motor 14 is operated with low speed to move the wiper blade into containing state.