A variable speed unit is driven by a drive unit to make a tooth-missing large gear of a sheet feed tooth-missing stage gear mesh with a small gear of an input stage gear rotating at a constant speed, to then rotate a rotating shaft of the feeding roller and a cam at a first speed to lift an intermediate plate. If a sheet stacked on the intermediate plate is pressed against the feeding roller, the variable speed unit makes a large gear of the input stage gear and a tooth-missing small gear of the sheet feed tooth-missing stage gear mesh with each other, so that the rotating shaft of the feeding roller is rotated at a second speed faster than the first speed to rotate the feeding roller at a fast speed.