To prevent the operability of an automatic machine from being spoiled by rotating a friction roller, which is pressed against a conveyor roller, reversely to the conveyance direction of a medium during its conveyance, and separating a conveyor-roller side medium and a friction-roller side medium from each other.

A suction motor 7 and a conveyance motor 8 are driven at the same time to clamp the medium with a conveyor roller 3A and carry it to a conveyor roller 3B. When the front end of the medium 2 is nipped by the nip part of the conveyor roller 3B, a friction separation roller 3b is rotated reversely to the conveyance direction and the one separated medium 2 is sent to a conveyor roller 3C. Further, when an optical read part 4 detects the front end of the separated medium 2, the suction motor 7 is stopped from being driven. Then the conveyance motor 8 is still driven thereafter and only the separated medium 2 is carried to the optical part 4 and a print head 5 and then guided to a collection box 6.