The comfort of sanitary napkins was examined by means of a questionnaire and through a wearing test. In the wearing test, the microclimate, both the temperature and humidity inside and outside of sanitary napkins, were measured every 10 seconds for 2h. Subjects consisted of 15 young healthy women who sat on chairs for 60 min, then stood and walked for 3 min, and again sat for 57 min under the experimental condition of 26°C and 60% RH. The results obtained were as follows: 1) The questionnaire showed that more than 60% of the subjects complained of sultriness discomfort during the menstruation period; 2) The wearing test showed that a high-humidity climate was formed in the space between the napkin and the skin, which caused subjective discomfort; 3) The correlation between the discomfort from the sanitary napkins and the difference in absolute humidity inside and outside of the napkins suggested that the discomfort from napkins could be reduced by a freer flow of water vapor.