Metal joint and building structure

The invention aims to provide a metal joint and building structure that is very reliable and has excellent stability as a junction and that does not lose yield resistance, initial stiffness, energy absorption capacity or the like in the junction when an excessive load is applied at the junction of a support member and horizontal member. [Solution] A metal joint (1) comprising a stationary plate (4) affixed to a side face of a support member (2), and a coupling plate (5), which is provided protruding from the stationary plate (4) toward the side of a horizontal member (3) and which is connected so as to be inserted into grooves (31) formed across the end face of the horizontal member (3) in the vertical direction, wherein the coupling plate (5) is provided with a plurality of coupling holes (52), into which cylindrical coupling instruments (8) are inserted into the grooves (31) so as to pass through the horizontal member (3), and a first cut portion (54) formed by cutting around the coupling holes (52). The fi