To provide a pair of men's underpants utilizing stretchability of a fabric at a low cost without problems of slippage and pressure by the fabric, satisfying fitting properties, moderate sense of relief, and holding properties without feeling of pressure, and excellent in feeling of wear and motion followability.

This pair of underpants has, in a longitudinal direction central part corresponding to the male privates of a front body 11, an expansion part 20 which is made of a single fabric with stretchability, and expands outside by seams at least with a cutting shape of itself to hold the male privates, and is sewn together with circumference fabrics 22 and 15. The expansion part 20 is sewn together with a crotch part 15 on an entering part 51 which partially enters the cross direction central part of the crotch in the longitudinal direction central part of the crotch part.