A conveyor, including: receiving trays; a conveyance mechanism; and a support supporting the trays, wherein at least one tray except a lowermost tray is supported so as to be selectively positioned at one of a receiving position and an upper position, wherein at least one lower tray except an uppermost tray includes a protruding portion attached to a tray body so as to be selectively positioned at one of a protruding position and a retracted position, and wherein the conveyor includes a force transmitting mechanism for effectuating at least one of (a) a retracting movement of the protruding portion of one of the at least one lower tray from the protruding position to the retracted position caused by an upward movement of an adjacent upper tray disposed just above and immediately adjacent to the one of the at least one lower tray from the receiving position to the upper position.