When the number of times of vehicle speed detections reaches a prescribed times “n”, a DR-side wiper blade is moved in such a way that when the front end side of a lip reaches a lower-side stop position APS1, the DR-side wiper blade is temporarily moved to a lower limit position for stop EPSL, then moved to an upper-side stop position APS2 and stopped there, and in such a way that when the front end side of the lip reaches an upper-side stop position APS2, the DR-side wiper blade is moved temporarily to an upper limit position for stop EPSU, then moved to the lower-side stop position APS1 and stopped there.