PURPOSE: To operate the tensile force along the axial direction of plural hook metal fittings installed to the width direction ends of a nonskid device for tire, along the full length of a fastening cord body rapidly and evenly, to the fastening cord body used to contract to the center of the tire.

CONSTITUTION: This fastening device 1 is composed by providing two cord locking mechanisms 20 which can hold both ends of fastening cord bodies 200 respectively in a device main body 2, and expansion members 50 such as a rubber cord to hook to the hooking metal fittings at adequate positions are connected at both ends of the fastening cord bodies 200 output from the fastening device 1. By the tensile force of the expansion members 50, both ends of the fastening cord bodies 200 are to be drawn out together from the fastening device 1 at the same time.