To provide a novel substance which can become an important marker substance in discussing and evaluating an influence or the like of generating a photochemical oxidant and to an atmospheric environment and to provide a method for measuring the same and a method for evaluating the atmosphere with the substance as the marker.

The peroxyacryloyl nitrate represented by a formula: CH2= CHC(O)OONO2 is provided. The method for measuring the peroxyacryloyl nitrate comprises the step of detecting the peroxyacryloyl nitrate by a gas chromatograph/negative ion chemical ionization mass analysis from the atmosphere. The method for evaluating the atmosphere comprises the step of evaluating the atmospheric state according to the detecting degree of the peroxyacryloyl nitrate.