Abstract: A base end of a hook plate is simply inserted into a column surface of a columnar receiving member for fixing. A hook of the hook plate is inserted into an inserted groove provided in an end of a crossing member such as a girder. Further, a bolt passing through the crossing member is received by the hook. As a result, a framework of the receiving member and the crossing member can be fixed. Alternatively, hook plates each having a circular outer periphery and provided in the hooked form are respectively inserted into inserted grooves provided in a receiving member and a crossing member. The respective hook plates are fixed by bolts so as to build a framework.