PURPOSE: To simplify the connecting work and firmly connect members together not to expose a connection section to the surface.

CONSTITUTION: A recess 13 is formed on the connection face 11 of one member A, a bag body 22 made of a flexible raw material is fitted to the connection face 21 of the other member B, the connection faces 11, 21 of the members A, B are brought into contact with each other while the bag body 22 is inserted into the recess 13, then a filler is pressed into the bag body 22, and the bag body 22 is expanded along the inner face shape of the recess 13. Stretching force in the connection direction is generated on the bag body 22 expanded by the filler, and the members A, B are connected together in the tightened state by the stretching force.