To solve the following problems: in conventional flip-up sunglasses using a coil spring, although the restoring force of the coil spring is simply utilized to achieve the rotating operation, there are troubles that components of the rotating operation part and the assembling process are increased in number, thereby, the cost is increased.

The low-cost, flip-up sunglasses which is smoothly rotated through good use of a frictional resistance force obtained by bringing the coil spring sagged beforehand in contact with a rotational operation shaft is achieved.