To provide a gas analysis device comprising: a cell； a light source； and a detector, wherein two or more types of gaseous components contained in the gas are measurement targets, a mid-infrared light with a wavelength that is caused to match the absorption spectrum of the measurement target gaseous components is output from the light source, and concentrations of the gaseous components are obtained based on light intensity detected by the detector. The gas analysis device sets a cumulative measurement time for the mid-infrared lights with the wavelengths for respective ones of the measurement target gaseous components； and controls at least one of an output time of the light source and a detection time of the detector in accordance with the cumulative measurement times, thereby efficiently measuring the plurality of types of gaseous components contained in the gas by using the mid-infrared lights with the plurality of wavelengths.
