To reduce a curing time with joined strength between members being held even just after the joining and to correct displacement of a joining surfaces due to dimensional accuracy, when the members are inter-joined using a dowel.

Diameter of a dowel hole 4 is larger than that of the dowel 3, so that an insert part 8 is not arranged in a desired adjusting direction to secure an adjusting region. The insert part 8 is inserted into a position in a direction substantially rectangular to the desired adjusting direction of the dowel 3 and the dowel hole 4, so that a claw 9 of a joining member 6 bites into the both to temporarily fix the both, and movement and fine adjustment are performed so as to make widths uniform of both a vertical frame (V) 1 and a lateral frame (H) 2.