GAS DETECTOR

PROBLEM TO BE SOLVED: To provide a gas detector capable of keeping a higher gas detection performance under high concentration gas.SOLUTION: A gas detector includes a gas sensor 20 to vary its electrical characteristic value (such as resistance) depending on a gas concentration of detection target gas, a heater 21 to heat the gas sensor 20 to a temperature range in which the gas sensor 20 has sensitivity to the detection target gas, and a signal processing circuit 10 to detect the detection target gas from the electrical characteristic value of the gas sensor 20. The signal processing circuit 10 controls a heating status of the gas sensor 20 with the heater 21, and stops the heater 21 heating the gas sensor 20 if a rate of change in the electrical characteristic value exceeds a predetermined threshold value when the electrical characteristic value varies toward a high concentration side.