Abstract: Provided is a snowboard binding in which a stopper function operates when a boot is removed and the stopper function is released when a boot is mounted, and a stopper device for a snowboard binding. The snowboard binding is provided with an urging body for rotatably urging a highback rearward, and configured so that when a lock lever of a lock mechanism is placed in an unlocked state by the rotational urging of the urging body, the highback automatically rotates rearward, and configured so that when the highback arrives at the rearward-rotation-limit position or near the rearward-rotation-limit position, a connecting cord of the lock mechanism is tensioned, the orientation in which the lock lever projects from the highback rear surface section is maintained, and the lock lever in this projecting orientation makes contact with the snow surface below a snowboard to bring about a slide-preventing effect.