It is an object of the present invention to provide a connector in which the connector can be inserted into or fixed to in advance the abutting surfaces of the structural members to be connected, an adjustment of direction of the connector is not required, its workability and installing work can be remarkably improved at the same time the connector inserted into and fixed during connection can be prevented from being pulled off and its superior high safety in shearing resistance is attained. This connector is comprised of a connecting plate 2 formed in a flat plate; a hollow tubular member 3 having its one end fixed to both surfaces of said connecting plate 2 and the other end opened; a branch pipe engage part 7 communicating from a side part of the base end of said tubular member 3 to hollow part; a hollow branch pipe 8 having an engage part 9 removably engaged with the branch pipe engage part 7 formed at at least one end thereof; and a fixing hole 12 formed at a predetermined part of the connecting plate 2.