The present invention provides a rotary stamping apparatus including a shaft member having a polygonal configuration in a cross-section perpendicular to its axis of rotation and holding a plurality of stamp cartridges faced outwardly; a gripper case for supporting the shaft member at its opposite sides, the gripper case having an invert U-shaped configuration in cross-section; an elevator frame slidably mounted within the gripper case and movable between an outer position in which the outer end of the elevator frame is positioned outwardly from a plane including one of the stamp cartridges located in its usable position and an inner position in which the elevator frame is retracted inwardly from the plane, the elevator frame being resiliently biased toward the outer position; a selector knob for rotating the shaft member to the desired position; and each of the stamp cartridges being capable of being detachably mounted on the shaft member by sliding the stamp cartridge in the plane of rotation of the shaft member.