PURPOSE: To detect the commodity at a commodity take-out port, by utilizing an extensible conductive element constituted of an extensible conductive sheet.

CONSTITUTION: When an acting force is applied to acting blocks 3 from above, an extensible conductive element 12 constituted of an extensible conductive sheet 1 acts so that a force is applied to both end parts of a leaf spring 2 to extend the curvature of the leaf spring 2 at the central part thereof. Whereupon, the extensible conductive sheet 1 is stretched to both end sides thereof to extend because electrodes 4, 4 are fixed to both end parts of the leaf spring 2. Therefore, when the resistance value of the extensible conductive sheet 1 between the electrodes 4, 4 at this time is measured by a resistance value measuring device 5, a lower resistance value is shown as the acting force to be applied becomes larger. The central part of the leaf spring 2 is fixed to a fixed block 6 to act as a fulcrum. By this method, the extensible conductive element 12 can convert the magnitude of the acting force applied to the acting blocks 3 to the change in electric resistance and, by reading this change, it can be detected that a canned beverage is sent to a commodity take-out port.