To provide: a gas flow path member capable of surely and easily connecting a gas device to a gas inflow part or a gas outflow part; and a gas detector capable of easily forming a predetermined gas piping structure and obtaining high maintenance performance.

This gas flow path member comprises a gas flow path for connecting a plurality of gas devices to each other used in a gas treatment apparatus. The gas flow path member is formed with a plurality of flow path chambers mutually partitioned, each of which is formed with a gas inflow part and a gas outflow part opening on a front surface or on a rear surface, between a front surface plate and a rear surface plate mutually connected and fixed. In two mutually adjacent flow path chambers, the gas devices are connected to a gas inflow part of one flow path chamber and a gas outflow part of the other flow path chamber. A gas sensor and a pump are connected to each other by the above gas flow path member.