PROBLEM TO BE SOLVED: To provide a method that estimates a skin age by extracting a specific value concerning an intercellular lipid from the spectrum of a horny layer of skin measured by noninvasive Raman spectroscopy, and by evaluating a change of a barrier function due to the aging from the specific value concerning the intercellular lipid.SOLUTION: An evaluation method of a skin age of the present invention includes the steps of: extracting a specific value concerning an intercellular lipid from the spectrum of a horny layer of a subject measured by Raman spectroscopy about a plurality of subjects and previously finding a statistical regression line representing a correlation between the specific value concerning the intercellular lipid and the age. Then, the skin of the evaluation object person is measured by the Raman spectroscopy, and the specific value concerning the intercellular lipid is extracted. Thus, the age, which is found by checking the specific value concerning the intercellular lipid of the evaluation object person against the regression line, is determined as the skin age of the evaluation object person.
