Abstract: A nose mask having either one of several types of mask parts with different functions selectively fitted to an installation shaft, usable without impairing the attractiveness of a nose, and formed so that, when the installation shaft is inserted from nostrils into nose vestibules a nasal septum is held so as to install the mask part. The mask part is engaged with the tips of the installation shaft by caps and stoppers, and cellulose sponges and filters are arranged alternately with each other. The mask parts can be classified into a plurality of groups according to functions, i.e those for underwater action without gas permeability and water permeability, those having fine-mesh filters formed of fiber material with gas permeability and excellent hygroscopicity and capable of filtering contaminated air, and those allowing liquid such as chemicals to be impregnated therein.