Provided is an apparatus for forming a tab from a moving original sheet with a laser beam. This apparatus is a tab forming apparatus in a tabbed electrode sheet producing apparatus (100) for moving, in one direction, an original sheet (1) including an electrode portion (1a) obtained by applying an active material layer to a long metal foil (4) and an ear portion (1b). This tab forming apparatus includes: a laser emission device (50) configured to apply a laser beam (L1) to the moving ear portion (1b) to cut out a tab (5) connected to the electrode portion (1a); an ear portion separating portion (70) provided at a position above or below a moving plane on which the electrode portion (1a) moves, on a downstream side of an irradiation point (Pm) of the laser beam (L1), so as to cause a take-up angle (α) to occur at the irradiation point (Pm) between the ear portion (1b) from which the tab (5) has been cut out and the moving plane; and an ear portion collection portion (80) configured to collect the ear portion (1b) in synchronization with the movement of the original sheet (1), while applying tension to the ear portion (1b) from which the tab (5) has been cut out with the laser beam L1.