An image forming apparatus having a sheet material conveyor includes an image forming unit, a sheet material conveyor on which an image is formed by the image forming unit, a conveying path situated at a downstream side of the conveyor for guiding the sheet material which may be upwardly curved, a paper discharging tray for supporting the sheet material guided through the conveying path, discharging rollers situated at an exit side of the conveying path which can switch between a forward rotation for discharging the sheet material onto the paper discharging tray and a reverse rotation for returning the sheet material in a direction opposite to the direction of discharge, and a reconveying path for accepting the sheet material returned on the conveying path by the reverse rotation of the discharging rollers and for guiding again the sheet material to the image forming unit.