a sheet supply apparatus includes a sheet supply member for supplying printing sheets , a separating member movably situated adjacent to the sheet supply member , a pressing member movably situated adjacent to the separating member , an urging device disposed near the pressing member for urging the pressing member toward the separating member so that the separating member contacts the sheet supply member , and an adjusting device connected to the urging device for adjusting an urging force exerted on the pressing member by the urging device . the adjusting device includes a rotationally operating portion and a rotationally adjusting portion connected to the rotationally operating portion . the rotationally adjusting portion is situated adjacent to the pressing member and the urging member to adjust the urging force while being operated by the rotationally operating portion .