Abstract: A sheet film developing device with a dark chamberside introduction of sheet films to be developed comprises a developing unit, a unit for moving a sheet film to the developing unit, a sheet film supplying unit for supplying sheet films to the developing unit, the sheet film supplying unit including a sheet film stacking device provided with a loading flap openable from outside for inserting a sheet film stack, a pulling device for pulling individual sheet films at a side of a stack opposite to the loading flap, an individual sheet supporting surface associated with the loading flap, a sheet film transporting unit arranged after the pulling device and the individual sheet supporting surface operative for guiding a sheet film from one of the individual sheet supporting surface and the sheet film stacking device in a transporting direction, and a sheet film sensing unit located in a transporting path defined by the sheet film transporting unit and operative for determining the presence of a sheet film on the in