A photoacoustic gas detector may include: a gas chamber configured to receive a gas to be analyzed therein, an excitation element configured to selectively excite gas molecules of a specific type that is to be detected in the gas received in the gas chamber in a time-varying fashion, thereby generating pressure differences, a sensor configured to detect pressure differences generated by the excitation element, and a pump configured to pump gas between the exterior of the photoacoustic gas detector and the gas chamber.