The present invention is directed to providing a paper carrying mechanism for a printing device, in which the number of parts and assembly processes can be reduced, and which the carrying deviation does not occur even if a recording medium is reciprocally carried. The paper carrying mechanism for a printer comprises a rotatable carrying roller 2, and a rotatable pressing roller 3 arranged above the carrying roller 2. The pressing roller 3 is arranged to have a gap G of ½ of the thickness of a recording medium 5, between the pressing roller 3 and the carrying roller 2. When the recording medium 5 is carried to the gap G, the pressing roller 3 is pushed up so that the carrying roller 2 is pressed against the recording medium 5 due to the weight of the pressing roller 3.