A shifting mechanism includes a guide plate, a bearing, a rotating shaft, a delivery roller, and a bearing unit. The shifting mechanism delivers a sheet of paper along a delivery passage and offsets the sheet horizontally and perpendicularly to the passage while delivering it. The guide plate has an opening forming part of the delivery passage and an end hole formed through the front end of the plate horizontally and perpendicularly to the passage. The rotating shaft extends through the end hole. The delivery roller is fixed to the rotating shaft. The sheet passes through the nip between the delivery roller and the guide plate. The bearing unit extends movably through the end hole and includes a sleeve, which supports the rotating shaft horizontally and perpendicularly to the delivery passage. The bearing unit rotates the rotating shaft.