PURPOSE: To make a printer as compact as possible and to mount the same on a desk side by classifying various papers to control the output of an ultrasonic feed means.

CONSTITUTION: A housing H2 is received in the receiving part 99b of a desk 99 and, when a printer 3 is used, it can be drawn out to a desk side 99a before use. When printing paper P is inserted in the insertion port 3a of the printer 3, the thickness or wt. thereof is detected by a detection means 7 and a fuzzy controller 8 executes fuzzy inference on the basis of the detection signal of the means 7 to output a correction signal to an output controller 8a and controls the output of a feed means Z1 so that the upper surface of the paper becomes flush with the under surface of the insertion port 3a and the under surface of a discharge port 3b. The feed means Z1 and a feed means Z2 are formed in parallel and the paper can be smoothly fed to a paper discharge part B by the small output of an ultrasonic feed means. The manuscript paper X fed on the feed means Z2 is irradiated with the light of an LED array 53 through a sensor hole 4.