To obtain a cylinder assembly-type driven formwork whose material and transport costs are low, which can be assembled and fitted easily, by using a cylindrical formwork material made by combining multiple multilayered plastic boards which are circular-arc in cross section into a circular form.

A cylindrical formwork 1 is formed by combining multiple multilayered plastic boards 11, 12 which is circular-arc in cross section, in a circular form so that a prescribed inner diameter R1 may be obtained. When building a body such as a foundation underground beam and a basement floor water tank, to form a through hole in a boundary to be divided, the cylindrical formwork 1 is placed in a prescribed position, both ends of which are fixed to lagging formworks, and concrete is placed. It is desirable that the multilayered plastic boards 11, 12 are formed in a double-wall structure which contains an air or gas layer, the inner wall is made a bottom, and dents opened in the outer wall are provided in a row at a constant interval. It is desirable that a reinforced timbering material made of an external ring material and an internal ring material is provided in a detachable manner so that it may inscribe coaxially.