Provided is an epoch-making original sheet dividing method in which an original sheet is
cut while being conveyed and which enables a
continuous operation to be performed for a long period of time without occurrence of burrs at
cut end faces, without scattering
cutting dust, and without time and effort for component replacement.The original sheet dividing method is an original sheet dividing method for
cutting an original sheet 1 having an active material layer applied to at least one surface of a long
metal foil 4, with a
laser beam L in a longitudinal direction. The original sheet 1 is continuously moved. While the original sheet 1 is moved, the
laser beam L is applied to the original sheet 1 to melt the original sheet 1 at an
irradiation point P. At a downstream side of the
irradiation point P of the
laser beam L, one divided original sheet 1s is pulled upward relative to a feed surface of the original sheet 1, and adjacent another original sheet 1t is pulled downward relative to the feed surface of the original sheet 1, thereby separating the slit original sheets 1s and 1t adjacent to each other at the
irradiation point P.