The present invention relates to a joining structure at a joining portion of a couple of members. A belt type flat surface portion (11) provided to one member (10) and an opposing flat surface portion (21) provided to the other member (20) are joined with each other via a plurality of plate springs (14) allocated along the longitudinal direction of the belt type flat surface portion. Here, a plurality of plate springs are directed diagonally to the longitudinal direction of the belt type flat surface portion. Accordingly, the plate springs can be allocated with higher space efficiency and moreover close contact can be improved and reduction in cost can also be realized.