To provide a device which enables a pillar and a horizontal member such as a sill in a woody building to be strongly joined with each other.

A cylindrical joint fitting 4 with a bottom which is fitted in an engaging hole 3 that is vertically formed at the horizontal member such as the sills is fastened to the horizontal member at its bottom plate 4a by a bolt 6 passing through the horizontal member and a nut 8 screwed to the bolt 6. The upper part of the joint fitting 4 which protrudes from the horizontal member is fitted in a circular slit 10 formed at the end face of the pillar 9, and the upper part and the pillar 9 are fixed with each other by a joint rod 15A driven into the pillar 9.