In a sheet separating mechanism, adapted to be positioned in an imaging device, for forming an image through an electrophotographic system, using a fan-folded sheet on which a visible image having been formed on a predetermined photoconductive member is to be transferred by means of a charger member arranged to be retractable from an operating position at which the transferring operation is to be executed onto the fan-folded sheet being fed in a predetermined direction, for separating the fan-folded sheet from the predetermined photoconductive member when the charger member is retracted from the operating position; the sheet separating mechanism comprising a pressing member arranged to be contacted with an image-forming surface of the fan-folded sheet for pressing the fan-folded sheet. Thus, the fan-folded sheet is forced to be separated from the predetermined photoconductive member when the charger member is retracted from the operating position.