1, stand by. Put the autoclave on a 2000-watt electric furnace, or a gas furnace or coal furnace with sufficient firepower, and add water to the pot to the water level mark line. Wrap the culture medium and the empty glassware to be sterilized with kraft paper and put them in the pot jacket. Articles should not be put too much and crowded, and a third of the space should be reserved in the pot. Then close the cover, tighten the screws on the cover diagonally and evenly, and close the air valve on the cover.

2, heating. Light the heat source and start heating. When the pressure gauge on the pot cover reaches 0.5 kg/cm ㎡, open the air valve to discharge the cold air in the pot until the pressure gauge drops back to "0", close the air valve and continue heating. When the pressure gauge rises to the required pressure (generally 1 kg/cm ㎡), start to calculate the sterilization time. At this time, the heat source should be properly turned down and the size of the heat source should be constantly adjusted to keep the pressure at the required value. After the holding time is reached, the heating should be stopped to naturally reduce the pressure in the autoclave.

3. End. When the pressure gauge drops to "0", loosen the screw, half open the lid, dry the lid paper with the waste heat in the pot, and take out the sterilized articles after 10 minutes.