PURPOSE: To facilitate the repeated use of patterned forms by enabling concreting using the patterned forms to be carried out without strength problems by enabling a separator for holding the interval between the forms to be installed without boring holes through the pattern-forming recessed portions of the patterned forms.

CONSTITUTION: A plurality of patterned forms 1, each of which has a pattern- forming recessed portion 2 having a masonry pattern or the like and has a joint-forming projecting portion 3a at its peripheral edge, are arranged continuously and in parallel and bonded to the surface of placement of concrete in such a way that the positions of the forms 1 are alternately displaced with respect to a concrete formwork main body panel 10 along at least either vertical or horizontal direction. A separator 20 for holding the interval between the forms is placed at the joint-forming projecting portion 3a at the junction of the patterned forms 1, 1 whose positions are displaced with respect to the main body panel 10, and predetermined concrete formwork A is constructed to place concrete.