To always surely detect a positioning mark in a battery enclosure tube without depending on the color of the positioning mark so as to perform cutting in a predetermined cutting position.

In a long battery enclosure tube 1, a cutting position mark 1b and a positioning mark 1c are printed, and the positioning mark 1c serves as a guide for controlling travel or movement of the battery enclosure tube 1 so that the cutting is always carried out at the cutting position mark 1b. That is, the positioning mark 1c of a traveling battery enclosure tube 1 is detected by means of a position detection mechanism such as a photoelectric sensor, and in response to the detection of the positioning mark 1c, the tube is fed by stipulated (specified) dimensions by means of a pulse motor or a servo motor which is adjusted each time, and then cutting is carried out in the cutting position mark 1b.