Gas flow

Patent Pending PROBLEM TO BE SOLVED: To provide a method and device for visualizing the gas flow, capable of visualizing even the oxygen gas flow and air flow that pass through the gas diffusion layer, with even for the pores of the layer that are very small. ; SOLUTION: On the oxygen-quenching material layer 3 which is made to closely contact the gas diffusion layer 1a the gas supply means 11-13 which supplies visualizing object gas, containing oxygen, and a gas for comparing are supplied alternately, and an irradiation device 15 that irradiate an exciting light 15a on the surface of the oxygen-quenching material layer 3 are provided, and the imaging device 16 and the display device 17 are provided.