A one dimension all-metal slab waveguide gas laser comprises a slab waveguide gas discharge area and an optical resonator disposed in a metal vacuum chamber. The gas discharge area is formed by a top and a bottom metal electrodes and metal supporting blocks insolated with the electrodes. A metal liner plate and a metal press plate are sequentially disposed on upside of the metal electrodes. A metal supporting plate is disposed at underside of the metal electrodes. The metal top electrodes are connected with a supply power through link pins of the metal electrodes. An output mirror and a feedback mirror are respectively arranged at two sides of the optical resonator. An output window of the laser is disposed in the vacuum chamber. The present one dimension waveguide gas laser has advantages of good quality of high thermo conducting and simple processing as well as low cost, and can avoid appearing modulation of the output power of the laser which is caused by high order mode of the guide in current two dimension slab guide laser, thereby the quality of optical beam of the laser is improved.