PURPOSE: To obtain an infrared gas analyzer constituted so that a plurality of infrared sensors are arranged with respect to a measuring cell having a small caliber with allowance in a dispersed state and a gas filter is easily arranged in combination with the specific sensor.

CONSTITUTION: In an absorbancy type infrared gas analyzer wherein an infrared ray source 2 is arranged on the incident side of a measuring cell 1 filled with sample gas and a plurality of infrared sensors 2 corresponding to the component gases to be measured in the sample gas and a plurality of band-pass filters 7 are provided on the emitting side of the cell 1, a light distributing cell 9 equipped with a reflecting mirror 9d dividing the beam transmitted through the measuring cell 1 into two directions is arranged behind the emitting surface of the measuring cell 1. A plurality of the infrared sensors 6 and gas filters 10 are arranged to the emitting edges in two directions of the light distributing cell in a distributed state to measure and analyze various component gases in the sample gas.