PURPOSE: To provide a connecting material minimized in a protrusive part in a shape of a connecting part of a structural material so that the fellow structural materials can be firmly connected.

CONSTITUTION: A connecting material, which is for connecting the fellow long scaled structural materials, has an end face connecting part 3 of receiving an end face of the one structural material intended to be connected and a side face connecting part 5 of receiving a side face of the other structural material intended to be connected. In a reverse side of the end face connecting part 3, a bolt insertion hole 3a inserted through this end face connecting part 3 an a deep counterbore part 3c of inserting a bolt head part are formed, and in the periphery of the bolt insertion hole 3a on a surface of the end face connecting part 3, a vertical protrusion 3b relating to this surface is formed. The side face connecting part 5 is formed in a surface in an opposite side to the end face connecting part 3, and this side face connecting part 5 has a connection structure of angle corresponding to a plurality of side surfaces of connecting to each other this structural material matched with its side surface shape.