PURPOSE: To prevent the deviation of position without stretching or deforming a cut-to-size tire constituting material by providing mechanisms to drive independently conveyors on the upstream side and the downstream side on a plurality of upper and lower stages and installing a device for separating the cut-to-size tire constituting material from a following tire constituting material.

CONSTITUTION: As a breaker is transferred on first and second conveyors 18 and 19 in the state of being attracted by a permanent magnet of a belt supporting plate, the same is transferred in the state of being positioned without meandering, and cutting-to-size is carried out accurately. When cutting-to-size is completed, the first and second conveyors 18 and 19 are driven. As a separating roll group 31 is rotated, a triangle rear end section of a cut-to-size breaker 12a is passed without slipping while rotating the separating roller 31 group, and the cut-to-size state is retained without elongation or deformation.