IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED : To provide an image forming apparatus capable of processing normal job. SOLUTION : A hydraulic valve operation device delivers a sheet S on which image is formed on one face up to the halfway of a sheet loading means 119 by a sheet inversion means 120, then switches it back, and conveys it to a re-conveyance part 100D conveying the sheet S to an image formation part 100B again when forming image on a rear face of the sheet S on which image is formed on one face. A control means for controlling image formation operation stops image formation operation for a new sheet when detecting that sheet loading amount of a sheet loading means 119 reaches predetermined amount based on signals from a detection means 127 after forming the image on the rear face and controls to continue image formation operation for the rear face of the sheet on which the image is formed on one face.