A medium conveying apparatus includes a medium tray, a pair of side guides to regulate a width direction of a medium, and a housing on which the medium tray is located and including a conveyance path capable of conveying the medium placed on the medium tray. The pair of side guides are located on the medium tray so that outer ends of the pair of side guides can be positioned from an inside of the medium tray to an outside of a maximum width of the medium tray. The conveyance path can convey a medium having a width of an inside of the pair of side guides even when the outer ends of the pair of side guides are positioned outside the maximum width of the medium tray.