NITROGEN OXIDE CONCENTRATION MEASUREMENT DEVICE

This nitrogen oxide concentration measurement device measures a nitrogen oxide concentration by shining light on a sensor produced by distributing a metal complex of porphyrin or a derivative thereof over a base material, and detecting the amount of light of a specific wavelength, said device comprising a light source that shines light at a nitrogen oxide concentration measurement sensor, a light detector that detects the amount of light of a specific wavelength out of all the light transmitted or reflected by the nitrogen oxide concentration measurement sensor, and a controller that corrects the detection result at the light detector so as to match the amount of light of a specific wavelength outputted from the light detector during exposure to a zero gas to a corrected value.