PURPOSE: To shorten a construction period by installing a non-slip part to the top and placing concrete into a form which is continuously provided with an upper horizontal part and a vertical part to which the non-slip is installed to the top.

CONSTITUTION: An upper horizontal part 1, which is made of glass fiber reinforced concrete, is installed so that it may be a part of a tread after the execution of work. A vertical board 2, which forms a riser after it is constructed, is continuously installed to the upper horizontal part 1, thereby forming a staircase placement type form A. Furthermore, a non-slip part 3, which is made of tiles or the like and provides a groove on the top of the upper horizontal part 1, is one piece-molded on the top of the upper horizontal part 1 and the vertical part 2 is laid out so that it may be positioned at the riser of the staircase and then concrete is placed. Therefore, this construction makes it possible to use the form as a form during concrete placement and use the form as the riser and the tread of the staircase as well even after the concrete placement.