To prevent, in a paper feeder for feeding a continuous printing paper having feed holes at an end portion thereof, the disadvantage that the paper feed holes slip off tractor pins, without imposing load on the continuous paper.

A paper feed mechanism feeds the continuous printing paper having the feed holes at the end portion thereof by allowing the pins 11 engaged into the feed holes to rotate in a direction to feed the continuous paper (paper conveyance direction B) by a spline shaft 2. A shaft holder 4 for holding the spline shaft 2 is movable in a vertical direction with respect to the paper conveyance direction B.