To enhance: the productivity without drastically increasing the setting area of a forming machine; and the forming precision of a formed product in a cold roll forming machine.

The cold roll forming machine includes a forming roll apparatus A, one pair of right and left sides mandrel apparatuses N1, N2 and one pair of right and left sides back-up roll devices B1, B2 and a centering roll device J, with which the centerings of respective works W formed at both sides of forming rolls FR are simultaneously performed, and two works W can simultaneously be roll-formed at the facing part of the forming rolls FR in the forming roll apparatus A.