A METHOD FOR MOUNTING A SHEET LIKE MEMBER ONTO A MOUNTED MEMBER BY UTILIZING A FASTENING DEVICE AND MOUNTING STRUCTURE

[Problem the Invention is to Solve] The object of the present invention is to provide a fastening device for a sheet-like member which is capable of achieving the sensing of a click to show the completion of fastening, in an attempt to mount a sheet-like member onto a mounted member. [Means to Solve the Problem] A fastening device for a sheet-like member for mounting a sheet-like member onto a mounted member comprises: cylindrical shaft member (12); flange (11), which is provided at the lower end portion of the shaft member and which has a greater diameter than that of the shaft member; a plurality of holding pieces (21), which are provided at the upper end portion of the shaft member and which are capable of being bent radially outward from hinge (22); head member (23), which connects the upper ends of the holding pieces together; guide member (24), which extends from the head member in the downward direction; bottom member (26), which is provided below the guide member; and a pair of anchor leg locking members (25), which extend obliquely upward from the bottom member. On the inner peripheral portion where the flange is connected to the shaft member, thin members (11a), with a thickness less than that of the outer peripheral part, are provided, and the flange is easily bent. Built-up members (28) are provided at a root part where the anchor leg locking members are connected to the bottom member, and the anchor leg locking members are hardly bent. As the load for pushing in the fastening device becomes smaller towards the completion of mounting beyond the peak load, the sensing of a click, to show the completion of mounting, can be achieved.