To provide a roll position regulating structure of a printer capable of simply and rapidly removing a printing sheet interposed between rolls.

The printer 10 comprises a plate cylinder 40 in which an ink is transferred via an anilox roller 20, and an impression roller 50 for substantially contacting its outer peripheral surface with the cylinder 40. A disc member 56 is disposed at two axial positions of the cylinder 50. The member 56 is vertically movably supported to a side plate frame 14 via a slide block 58. A cam 70 is disposed so as to be contacted with an outer peripheral surface of the upper end of the member 56, and the cylinder 50 is relatively displaced to the cylinder 40 in a vertical direction of the member 56 in the case of rotating the cam 70.