PURPOSE: To aim at carrying out everything necessary to set chains to a tire at the obverse side of the tire, by making a ringlike chain connecting with one side of the side chains of a chain proper into a ring form in which the other side is released.

CONSTITUTION: A chain proper 1 is made up of a side chain 2' coupled in ring form in advance, a side chain 2 to be released via fastenings 2a and 2b and a cross chain 3. When the chain 1 is set to a tire T, first of all the chain 1 is spread out annularly and the tire T is positioned at its center. Next, the chain 2' is lifted upward along the obverse side TA of the tire T and moved to the reverse side TB via a tread TC. Finally, fastenings 2a and 2b of the chain 2 are locked from the front side and then the chain 1 as a whole is tightened.