Provided are a gas detection method and a gas detector which have a high durability to silicone poisoning and is capable of detecting the type and the concentration of a target gas to be detected with certain accuracy even when the detector is used in an environment where a silicone compound exists. The gas detector employs a contact combustion-type gas sensor which includes two gas detection elements, each intermittently driven, and in which only one gas detection element is supplied with a gas through a silicone removal filter. Acquired in an energization duration of each of the gas detection elements are two or more pieces of output data by the one gas detection element and two or more pieces of output data by the other gas detection element, which constitutes output variation patterns for a test gas. The output variation patterns are contrasted to a reference output variation pattern of each of four largely divided types of reference gases of a paraffinic hydrocarbon gas, a solvent gas, a hydrogen gas, and an argon gas, with the reference output variation patterns being acquired in advance, thereby identifying the type of the target gas being detected in the test gas.