To provide a form for molding a secondary concrete product which is assembled by actuating a link mechanism in place of a form in which a side form has been fixed by bolting.

In a form, a molding space is formed by a base 1, an inner surface form 2 having an inner surface plate 21 which forms the inner surface of a secondary concrete product and an inner surface plate supporting member 22 to which the plate 21 is fixed, and a side mold form 3 having a side plate 31 for forming the side of a secondary concrete product and a side plate supporting member 14 to which the side plate 31 is fixed. The form 2 is installed vertically movably to the base 1, the form 3 is attached rotatably to the base 1, a lift 4 for moving the form 2 vertically is installed, and a means equipped with a link mechanism 5 for forming a molding space by rotating the form 3 linked with the vertical movement of the form 2 by connecting the form 2 and the form 3 or for demolding is provided.