Microorganisms must be kept at a certain temperature to allow them to multiply after they are planted in the culture media. The instruments used for this purpose are called an oven or incubator. The constant temperature of the incubator should be the same at all times and must not be greater than ± 0.5 ° C. The incubator is set to the desired temperature. It maintains the same degree continuously thanks to its thermostat. The temperature is controlled by a temperature control unit attached to the device.