PURPOSE: To simply and rapidly evaluate the oxidation life of a sample by holding the sample, at a constant temp. and measuring at least one of the temp., odor intensity and transmissivity thereof.

CONSTITUTION: The sample 1 in a sample container 10 is held at a predetermined temp. in a thermostatic tank 20 and the temp. of the sample 1 is measured by a temp. sensor 30 to be displayed and recorded by a recorder 31 and the odor intensity of the sample 1 is measured by an odor sensor 40 to be displayed and recorded by a recorder 41. When the measurement of the temp. or odor intensity of the sample 1 is continued, the temp. or odor intensity rises suddenly at a time when the sample 1 reaches oxidation life. The time from the start of measurement to a deflection point is measured to be set to an oxidation life time. By this constitution, the oxidation life of the sample can be relatively easily and rapidly evaluated. By blowing oxygen in the sample under stirring to accelerate the oxidation of the sample, a measuring time can be shortend.