PURPOSE: To improve execution ability by arranging a form body comprising a peripheral wall section whose outer peripheral contour is equal to the contour of the face of a pillar form and the horizontal flat plate section extending from the lower end of the peripheral wall section to the outside at the position on which a pillar is scheduled to be installed, and assembling the pillar form while using the form body as a reference.

CONSTITUTION: A frame-like metal fitting 1, which comprises a peripheral wall section 2, the contour of the outer peripheral face of which is equal to the contour of the face of a pillar form and the flat plate section 3 which orthogonally extends from the outer periphery of the lower end of the peripheral wall 2 to the outside, is formed. In the case where the floor slab is finished, the metal fittings 1 are fixed to the positions on the floor slab on which pillars are scheduled to installed. In the case where the floor slab is not yet finished, the metal fittings 1 are arranged on the positions on which pillars such as columns and beam connection sections are scheduled to be installed and also fixed there with the upper face of the plate 3 leveled so as to be equal to the level of the execution scheme face of the floor slab. Then, concrete is placed on the floor, in addition, after reinforcing bars are arranged to form a pillar, the face of the pillar form is positioned in contact with the outer face of the wall 2 and is assembled. With this constitution, accuracy and work efficiency can be improved, and the level of the floor slab can be precisely executed, and concrete can be prevented from leaking from the lower end of the pillar form.