Printer having swingable printing rings which are selectively swung against a platen to print a line of selected characters on a paper by selecting a desired character from a plurality of characters provided on the periphery of each printing ring during the rotation thereof about its axis. Each printing ring is rotatably supported on a swingable printing ring supporting lever which is in turn swingably supported on a driving shaft. A plurality of driving gears are secured to the driving shaft and each of the driving gears meshes with a gear integral with the respective printing ring so as to rotate the same about its axis for selection of a desired character during the rotation thereof. Each printing ring supporting lever is urged by a spring so as to move the printing ring thereon apart from the platen. A plurality of driving levers are swingably supported on the driving shaft and each driving lever is engaged with the respective printing ring supporting lever.