A wiper device includes: lock grooves provided at an arm head and recessed toward both sides in a wiping direction of a wiper blade; and lock claws provided at an arm shank and protruding toward both sides in the wiping direction of the wiper blade. By concave-convex mating of the lock grooves and the lock claws with each other, the arm shank is restricted from rotating by degrees (about 22 degrees) or more with respect to the arm head, and a state in which the arm shank stands up by degrees (about 20 degrees), which is smaller than degrees, with respect to the arm head is maintained.