To provide a concrete form device used for depositing concrete to construct a concrete structure, an insulating molded body attached to a form to secure a heat insulating performance necessary for the concrete form device, and a method of assembling the insulating concrete form device in which the insulating molded body is used.

In this concrete form device, the insulating molded bodies 2 are fitted, respectively, into the blocks 4 of a concrete form having, on the rear surface of the surface plate 1a, peripheral ribs 1b, 1c vertically extending along the outer peripheral edge of the surface plate 1a and intermediate ribs 1d, 1e partitioning the inside of a frame surrounded by the peripheral ribs. The blocks are partitioned by the peripheral ribs and the intermediate ribs on the rear surface. Each insulating molded body 2 is formed so that the side surfaces thereof are brought into contact with the inner surfaces of the ribs 1b, 1c and 1d, 1e which form the block 4. has a thickness equal to or smaller than the height of the ribs, and includes a plurality of recesses 2a at the positions in contact with the outer peripheral sides of the rear surface of the molded body 2.