A rolled medium supporting mechanism includes a supporting member 210 that rotatably supports a rolled medium. The mechanism is provided with a plurality of abutting supporting members 230 arranged in the circumferential direction of the supporting member and supporting the rolled medium by making abutting contact with an inner peripheral face of a hollow shaft portion of the rolled medium when the mechanism is inserted into the hollow shaft portion of the rolled medium. The abutting supporting members are configured to be freely displaced in a roll-diameter direction in accordance with an inner diameter of the hollow shaft portion. With such a configuration, it is not necessary to have a separate component in order to adapt to core members having different diameters, but only displacement of the abutting supporting member is needed. Thus, it is possible to simplify the construction and provide easy handling properties.