To provide an attaching/detaching mechanism for a decorating member for a spectacle frame, the mechanism facilitating replacement of the decorating member, preventing displacement or separation of the decorating member, imparting a one-point accent easily to a frame design by means of the decorating member, and being easy to manufacture and effective in terms of cost.

The mechanism is composed of: an attaching member which includes a notch made in part of a ring surrounding a circular hole; and the decorating member, in which a surface plate with a decorative face and a back plate are connected via a connection piece. The connection piece for the decorating member and the ring of the attaching member compose a bayonet locking mechanism. With the connection piece for the decorating member inserted in the circular hole of the attaching member, the decorating member is rotated around its axis at the connection piece. Thereby, the connection piece can be locked in the attaching member.