PURPOSE: To obtain a paper feeding mechanism enabling the attaching of paper and printing condition to be simply set up only by operating a cam-operating lever by coupling a paper feeding roller, a paper pushing roller, and a paper stopper by using a specific type of cam mechanism.

CONSTITUTION: A paper feeding roller 4, a paper pushing roller 5, and a paper stopper 6 are operated by a cam 7 turning at the hole 9 as the center by an operating lever 8. When the operating lever 8 is vertically erected (i), the paper keeping roller 5 is contacted through a push arm 36 with the platen 1(mark 2 shown by chain line is printing paper), the paper feeding roller 4 is contacted through the paper feeding arm 20, and the paper stopper 6 is separated(printable state). When the lever 8 is counterclockwise turned about 30°(ii), the paper keeping roller 5 is separated from the platen 1. When the lever 8 is further turned about 30° to set it at the position of about 60° in the counterclockwise direction (iii), the paper stopper 6 is contacted with the platen 1 and the paper feeding roller 4 is separated(paper attachable state).