PURPOSE: To enable a buckle to be manufactured by one kind of member molding dies and members to be saved by reversing one of two same shape connecting members S, S for use.

CONSTITUTION: One of two same shape connecting members S, S is reversed so that a projecting piece 4 of one connecting member S is opposed to an opening 50 of the other member S into which the projecting piece 4 is inserted and then the projecting piece 4 is forcibly inserted into the opening 50. On the way of the forcible insertion, a locking part 40 is elastically deformed inside, while elastically recovered to the original state when the connecting members S, S are connected properly to each other and the outer surface of the locking part 40 projects from an operating outside opening 30. Under such a state, a support shaft 7 of one connecting member S is inserted into a support shaft inserting hole 8 of the outer connecting member S. The connecting members S, S are prevented from careless separation from each other by locking the locking part 40 in a wall constituting the inserting opening 50, and the connecting members S, S are prevented from deviation from each other by the relationship between the support shaft 7 and the support shaft inserting hole 8.