This study examines underwear purchase behaviors and the attitude of male consumers based on the degree of interest in appearance. Data research was conducted on 296 males in their 20s and 30s located in Seoul & Gyeonggi province. The SPSS 17.0 software program was used to conduct data analyses such as descriptive statistics, frequency analysis, factor analysis, cluster analysis, t-test, and $chi^2$-test. The results of this study are as follows: The degree of interest in appearance was identified with four factors; outfit management, confidence of figure, interest in clothing, weight control, and disinterest in appearance. Customers were segmented into two subdivisions: high and low interest in appearance. The factors derived from the factor analysis of underwear purchase motive included aesthetic, impulsiveness, and practicality. The purchase behavior of the group with high interest in appearance was highly motivated by aesthetics and impulsiveness. The factors derived from the factor analysis of underwear attitude included fashionability, comfortableness, and quality. Customers were segmented into the following three subdivisions: pursuit of comfortableness, pursuit of diversity, and normal. The type of high interest in appearance regarded fashionability and quality highly. Finally, the degree of interest in appearance showed significant relevance in purchase motive and underwear attitude for underwear.