To nonrotatably fix a shaft by bringing a jaw part of a shaft into pressure contact with the edge of a through hole of a mirror base by elastic restoring force of an elastic member, fixing the shaft to the mirror base, arranging a projecting part having a recessed part in the jaw part of the shaft, and arranging a recessed part into which a projecting part of the shaft enters on the periphery of the through hole of the mirror base.

The edge of a through hole 104 of a mirror base 100 and a jaw part 203 of a shaft 200 are brought into pressure contact with each other by elastic restoring force of a coil spring 25, and the shaft 200 is installed on the mirror base 100. The possibility that the shaft 200 rotates to the mirror base 100 when a mirror housing 300 rotatably tilts since three projecting parts 205 having a recessed part to which a steel ball 6 of the shaft 200 is fitted so as to be freely mountable-demountable respectively enter three hole parts 103 of the mirror base 100, is eliminated. A stopper projecting part 208 is arranged on the shaft 200 side, and a first - second stopper projecting part contact surface is arranged on the mirror housing 300 side, and a turning angle of the mirror housing 300 to the shaft 200 is regulated.