Provided is an image forming apparatus, which includes: a pressing lever and a pressing arm for pushing up a sheet stacking plate so that sheets stacked on the sheet stacking plate are brought into pressure contact with a sheet feeding portion; a lifter driving mechanism for driving the pressing lever and the pressing arm; and a setting mechanism disposed between the pressing lever and the pressing arm, and the lifter driving mechanism. The setting mechanism is capable of setting a pressure contact force for bringing the sheets stacked on the sheet stacking plate into pressure contact with the sheet feeding portion, to be appropriate for a size of the sheets to be stacked and an amount of the sheets to be stacked.