A substrate conveying system comprising: a substrate supply unit including a storage case including a pair of side walls facing each other, plural pairs of support elements provided on the side walls to support both end portions of plural substrates which have been transferred from a cartridge and loaded into the storage case such that the plural substrates oriented horizontally are arranged to be vertically spaced apart from each other, and a lower opening provided on a lower surface of the storage case, and a down unit which moves the storage case down; a lift unit having one or more ejection holes which are provided as points or to extend in a conveying direction of the substrates, from at least a region between the pair of side walls of the storage case to a region which is other than the region between the pair of side walls, when viewed from a vertical direction, and eject a gas upward, the lift unit being configured to lift-up the substrate supported on the support elements by a pressure of the gas ejected through the one or more ejection holes, when the down unit moves the storage case down; a conveying unit and a restricting section extending in the conveying direction and configured to restrict positions of the substrate being conveyed by the conveying unit, the positions being in a direction perpendicular to the conveying direction, when viewed from the vertical direction; characterized in that the conveying unit includes a pair of endless belts each extending through the region between the pair of side walls of the storage case of the substrate supply unit and along the one or more ejection holes of the lift unit which are provided as points or to extend in the conveying direction, when viewed from the vertical direction, plural hook elements provided on the endless belts to extend upward such that the hook elements are arranged at intervals which are larger than a dimension of the substrate in the conveying direction, and placed between the support elements of the pair of side walls when viewed in the conveying direction of the substrate, and a drive section for rotating the pair of endless belts, the hook elements being configured to push in the conveying direction upstream end portions of the substrate in the conveying direction, in a state in which the substrate is lifted-up by the pressure of the gas ejected through the ejection holes. a substrate supply unit including a storage case including a pair of side walls facing each other, plural pairs of support elements provided on the side walls to support both end portions of plural substrates which have been transferred from a cartridge and loaded into the storage case such that the plural substrates oriented horizontally are arranged to be vertically spaced apart from each other, and a lower opening provided on a lower surface of the storage case, and a down unit which moves the storage case down; a lift unit having one or more ejection holes which are provided as points or to extend in a conveying direction of the substrates, from at least a region between the pair of side walls of the storage case to a region which is other than the region between the pair of side walls, when viewed from a vertical direction, and eject a gas upward, the lift unit being configured to lift-up the substrate supported on the support elements by a pressure of the gas ejected through the one or more ejection holes, when the down unit moves the storage case down; a conveying unit and a restricting section extending in the conveying direction and configured to restrict positions of the substrate being conveyed by the conveying unit, the positions being in a direction perpendicular to the conveying direction, when viewed from the vertical direction; characterized in that the conveying unit includes a pair of endless belts each extending through the region between the pair of side walls of the storage case of the substrate supply unit and along the one or more ejection holes of the lift unit which are provided as points or to extend in the conveying direction, when viewed from the vertical direction, plural hook elements provided on the endless belts to extend upward such that the hook elements are arranged at intervals which are larger than a dimension of the substrate in the conveying direction, and placed between the support elements of the pair of side walls when viewed in the conveying direction of the substrate, and a drive section for rotating the pair of endless belts, the hook elements being configured to push in the conveying direction upstream end portions of the substrate in the conveying direction, in a state in which the substrate is lifted-up by the pressure of the gas ejected through the ejection holes.