A fixing device (100) for a bicycle includes a base (10), a bracket member (20), a pin (30) and a band (40). When fastening of the band (40) is loosened, the bracket member (20) comes to be rotatable in a direction of an arrow DR20 with respect to the base (10), allowing adjustment of a component angle. When fastened to the pipe by the belt (40), the base (10) and the bracket member (20) are engaged with each other and held in the engaged state, so that bracket (20) cannot be rotated in a direction of an arrow DR20 with respect to the base (10).