PURPOSE: To facilitate in/out handling of recording paper by generating a space between a paper feed roller and the recording paper when paper feed is not performed, while a circular paper feed roller is used in feeding the recording paper.

CONSTITUTION: A pressure plate lock means 10, having a swivel arm 41 and a cam 43 of pressing down a pressure plate 6 of pressing recording paper to a paper feed roller 4 locked to a downward standby position, is provided. As a drive source of this pressure plate lock means 10, a conveying motor 31 of driving a conveying roller 18 is used, to deliver the recording paper by the paper feed roller 4, and in the point of time a tip end of this paper arrives at the conveying roller 18, when forwardly rotated the conveying motor 31 for performing conveying the recording paper by the conveying roller 18, by forwardly rotating this conveying motor 31, the cam 43 is rotated to press the pressure plate 6 downward locked. By reversely rotting the conveying motor, the cam 43 is rotated to unlock the pressure plate.