MQ-8 gas sensor sensitive material used in clean air conductivity is lower tin dioxide (SnO2). When the sensor is present in the environment in which the combustible gas, the sensor’s conductivity increases with the concentration of combustible gases in air increases. Using a simple circuit can be converted to the change in conductivity of the gas concentration with the corresponding output signal. MQ-8 hydrogen gas sensor of high sensitivity, the monitoring of the other hydrogen-containing gas is also very satisfactory. The sensor can detect a variety of hydrogen-containing gas, in particular, city gas, is a low-cost sensors for a variety of applications.