Disclosed is an index that quantifies the comfortableness while being worn of a disposable diaper, and disclosed is a disposable diaper that displays this index and is stipulated by means of this index. The method for quantitatively evaluating the degree of comfortableness of a disposable diaper is provided with: a first step for acquiring first information that is obtained from the salivary amylase activity of the wearer when the disposable diaper is worn a second step for obtaining second information obtained from the physical characteristics that are linked with the sensation that the disposable diaper has when worn and a third step for obtaining the comfortableness when worn of the disposable diaper as third information by associating the first information and the second information. The second information is, for example, KES information of the aforementioned disposable diaper.
