An apparatus for the hot-chamber die casting of non-ferrous alloys essentially consists of a press (115) for the closing/opening of a mould (110, 111) and an injection group (112) comprising a pump body (102) immersed in a pot (124) of the molten alloy and in which an injector piston (116) slides, an actuator (108) connected to the injector piston (116), and a gooseneck formed of in the pump body (102) and ending with a heated extension (103) provided with a nozzle (104) for the connection to the mould (110, 111), two hydraulic jacks (114) being secured between the injection group (112) and the press (115) which is fixed, the injection group (112) being divided into a stationary bottom portion and a top portion movable on sloped guides (109) parallel to the longitudinal axes of the extension (103) and of the hydraulic jacks (114), the pot (124) being mounted on horizontal rails (120) and the hydraulic jacks (114) being secured to the pump body (102).