A sheet conveying apparatus with a skew feed correcting device including a first guide supporting one side edge of the sheet, an aligning device provided in the first guide and having an abutment portion and a first roller pair for causing the sheet to abut the abutment portion, a contact-separation device for separating and contacting the first roller pair, a second guide supporting the other side edge of the sheet, a positioning device for moving the first guide in a direction substantially perpendicular to a sheet conveying direction, a second roller pair downstream of the first and second guides, a slide device for moving the second roller pair in the direction, and a sheet detector. When conveying the sheet, the positioning device moves the first guide such that the abutment portion is at a predetermined distance from the side edge of the sheet, the sheet is conveyed while aligned by abutted against the abutment portion by the first roller pair, the first roller pair is separated by the contact-separation device based on the detection of the sheet detector, and the sheet is moved by the slide device so as to be returned by the predetermined distance while held by the second roller pair.