A gas detector for detecting a target gas in a test gas comprising a contact combustion-type gas sensor and an output processing unit, wherein: the contact combustion-type gas sensor includes a case in which two detection chambers (Sa, Sb) are formed that are partitioned by a partitioning plate, and two gas detection elements (20a, 20b) are each disposed in each of two detection chambers (Sa, Sb) that are partitioned from each other, the gas detection elements (20a, 20b) each having a catalyst carried by a carrier made of a metal oxide sintered compact firmly fixed to a temperature-measuring resistor, a gas inlet of the one detection chamber (Sa) is provided with a silicone removal filter configured to adsorb and remove a silicone compound, to permit paraffinic hydrocarbon gas or hydrogen gas to transmit therethrough and to remove a solvent gas, and a gas inlet of the other detection chamber (Sb) is not provided with a silicone removal filter, the target gas to be detected being a paraffinic hydrocarbon gas, a hydrogen gas or a solvent gas, and the output processing unit is configured to acquire concentration data of a target gas being detected in a test gas on the basis of output data provided by the one gas detection element disposed in the one detection chamber (Sa) and to acquire concentration data of the target gas provided by the other gas detection element disposed in the other detection chamber (Sb) and to output the higher one of the two pieces of concentration data as the concentration indication value of the target gas being detected, wherein in the case of the target gas being a paraffinic hydrocarbon or hydrogen gas detection element indicates the higher output value and in the case of the target gas being a solvent gas detection element indicates the higher output value. the contact combustion-type gas sensor includes a case in which two detection chambers (Sa, Sb) are formed that are partitioned by a partitioning plate, and two gas detection elements (20a, 20b) are each disposed in each of two detection chambers (Sa, Sb) that are partitioned from each other, the gas detection elements (20a, 20b) each having a catalyst carried by a carrier made of a metal oxide sintered compact firmly fixed to a temperature-measuring resistor, a gas inlet of the one detection chamber (Sa) is provided with a silicone removal filter configured to adsorb and remove a silicone compound, to permit paraffinic hydrocarbon gas or hydrogen gas to transmit therethrough and to remove a solvent gas, and a gas inlet of the other detection chamber (Sb) is not provided with a silicone removal filter, the target gas to be detected being a paraffinic hydrocarbon gas, a hydrogen gas or a solvent gas, and the output processing unit is configured to acquire concentration data of a target gas being detected in a test gas on the basis of output data provided by the one gas detection element disposed in the one detection chamber (Sa) and to acquire concentration data of the target gas provided by the other gas detection element disposed in the other detection chamber (Sb) and to output the higher one of the two pieces of concentration data as the concentration indication value of the target gas being detected, wherein in the case of the target gas being a paraffinic hydrocarbon or hydrogen gas detection element indicates the higher output value and in the case of the target gas being a solvent gas detection element indicates the higher output value.