A manufacturing machine to manufacture a product; the manufacturing machine comprises a feeding system to feed the products along a horizontal, straight processing path; wherein the feeding system comprises: a first processing conveyor, a second processing conveyor, which is arranged in series with the first processing conveyor along the processing path, and a transfer unit, which is interposed between the two processing conveyors (9, 10) and cyclically transfers the products from the first processing conveyor to the second processing conveyor, picking up the products in a pick-up station arranged in the area of the first processing conveyor and releasing the products in a release station arranged in the area of the second processing conveyor; wherein the transfer unit comprises: a plurality of trays, each having a series of seats, each designed to house a product; a moving system, which cyclically moves the trays of said plurality of trays between the pick-up station and the release station; a first transferring device, which is arranged in the pick-up station so as to transfer the products from the first processing conveyor to a tray of said plurality of trays; and a second transferring device, which is arranged in the release station so as to transfer the products from a tray of said plurality of trays to the second processing conveyor; the manufacturing machine is characterized in that the moving system comprises: a lifting device, which lifts the trays upwards along a lifting path, which is perpendicular to the processing path; a lowering device, which lowers the trays downwards along a lowering path, which is perpendicular to the processing path and parallel to the lifting path; and a first joining device, which is arranged between a top of the lifting device and a top of the lowering device and transfers the trays from the lifting device to the lowering device. the manufacturing machine comprises a feeding system to feed the products along a horizontal, straight processing path; wherein the feeding system comprises: a first processing conveyor, a second processing conveyor, which is arranged in series with the first processing conveyor along the processing path, and a transfer unit, which is interposed between the two processing conveyors (9, 10) and cyclically transfers the products from the first processing conveyor to the second processing conveyor, picking up the products in a pick-up station arranged in the area of the first processing conveyor and releasing the products in a release station arranged in the area of the second processing conveyor; wherein the transfer unit comprises: a plurality of trays, each having a series of seats, each designed to house a product; a moving system, which cyclically moves the trays of said plurality of trays between the pick-up station and the release station; a first transferring device, which is arranged in the pick-up station so as to transfer the products from the first processing conveyor to a tray of said plurality of trays; and a second transferring device, which is arranged in the release station so as to transfer the products from a tray of said plurality of trays to the second processing conveyor; the manufacturing machine is characterized in that the moving system comprises: a lifting device, which lifts the trays upwards along a lifting path, which is perpendicular to the processing path; a lowering device, which lowers the trays downwards along a lowering path, which is perpendicular to the processing path and parallel to the lifting path; and a first joining device, which is arranged between a top of the lifting device and a top of the lowering device and transfers the trays from the lifting device to the lowering device. a plurality of trays, each having a series of seats, each designed to house a product; a moving system, which cyclically moves the trays of said plurality of trays between the pick-up station and the release station; a first transferring device, which is arranged in the pick-up station so as to transfer the products from the first processing conveyor to a tray of said plurality of trays; and a second transferring device, which is arranged in the release station so as to transfer the products from a tray of said plurality of trays to the second processing conveyor; the manufacturing machine is characterized in that the moving system comprises: a lifting device, which lifts the trays upwards along a lifting path, which is perpendicular to the processing path; a lowering device, which lowers the trays downwards along a lowering path, which is perpendicular to the processing path and parallel to the lifting path; and a first joining device, which is arranged between a top of the lifting device and a top of the lowering device and transfers the trays from the lifting device to the lowering device. a lifting device, which lifts the trays upwards along a lifting path, which is perpendicular to the processing path; a lowering device, which lowers the trays downwards along a lowering path, which is perpendicular to the processing path and parallel to the lifting path; and a first joining device, which is arranged between a top of the lifting device and a top of the lowering device and transfers the trays from the lifting device to the lowering device.