PURPOSE: To cut and separate the end cover face of a roll of paper, by supporting a roll of paper on a support rotary unit and measuring the diameter by a measuring unit and positioning a cutting unit and a holding and transferring unit arranged at the end side of the support rotary unit on the basis of the measured value.

CONSTITUTION: Rollers 1a, 1b of a support rotary unit 1 are raisied while supporting a roll of paper A and the rollers 1a, 1b are rotated to rotate the roll of paper A to a specified direction The transferred distance until the contact sensor 2b of a diameter-measuring unit 2 reaches the outer surface of the paper A is calculated from the number of pulses of a pulse motor with an encorder. The diameter of the roll of paper is obtained by the measurement. After that, a holding and traveling unit 5 is driven and the lateral position of a cutting unit 3 and a holding and transferring unit 4 is adjusted and located. Finally, a cutter 7 is inserted between the end cover paper of the roll and the body thereof and the roll of paper is stably cut and separated.