Configuration, fabrication and performances of sealed-off CO2 waveguide lasers are reported, with a discharge length of 12.5 cm, the device consists of four BeO plates arranged in a square hole of 1.5 mm size, the cavity is 15 cm long. The maximum output power is 1W. At a gas pressure of 150 torr, the tuning width of p20 line was 500 MHz measured by optical heterodyne with two waveguide lasers.