PURPOSE: To prevent falling of each tread mounted over the upper surface of each beam member at the time of assembling a scaffold in the scaffold assembled with each footboard assembled on the upper surface of each beam.

CONSTITUTION: A channel section 1a is molded on the upper surface of a beam member made of FRP by means of simultaneous molding, a flange section 2a is molded on the side face of a footboard 2 made of FRP by means of simultaneous molding in such a way that it can be engaged with the channel section 1a, and a great number of footboards 2 are assembled while the falnge section 2a of each footboard 2 is being engaged with the channel section 1a of each beam member 1 when a scaffold is assembled, so that the scaffold can thereby be quickly assembled while each footboard 2 is being prevented from falling down. Besides, since the channel section 1a and the flange section 2a are molded simultaneously when a base member is molded, so that a connection structure high in strength can thereby be obtained.