PURPOSE: To constantly optimize the rain droplets removing rate in response to the vehicular speed in such way that the rain droplets removing rate of a wiper is automatically canged in response to the vehiclular speed.

CONSTITUTION: A speedometer circuit 10 to detect the vehicular speed is connected in parallel with a wiper speed control circuit 12 and a wiper movement interval setting circuit 14. The wiper speed control circuit 12 automatically changes the wiper moving speed in response to the vechicular speed on the basis of vehicular speed signal from the speedometer circuit 10. Besides, the wiper movement interval setting circuit 14 controls the wiper moving intervals to be constantly optimum moving intervals in response to the vehicular speed on the basis of vehicular speed signals from the speedometer circuit 10. Said circuit 14 can be set in three stages of A (light rain), B (medium rain), and C (heavy rain) in response to the rainfall, and setting of the moving intervals can be done taking their standards from the one when the vehicle is at a stop or running at low speed. In addition, the both circuits 12, 14 are connected to the wiper driving circuit 16, and the wiper driving circuit 16 moves the wiper on the basis of signals from the both circuits 12, 14.