An apparatus for manufacturing electrical energy storage devices, comprising a path for feeding material with intermittent feed and two machining stations arranged one after the other in the feed path, in which each machining station is movable on a linear guide at the command of a motor to vary its position along the feed path and enable the mutual distance between the two machining stations to be adjusted in function of the step of intermittent feed of the material, so that the apparatus is adaptable to the change in product size.