To provide the nose with a filter and to suck air through this filter.

This nose filter is a filter mountable into the nose and is a cylindrical nose plug 9 provided with many small holes 90 at its both end faces. An air permeable fiber body 92 is housed as the filter therein so that the air can be sucked from the nose. If material to make the brain good is put therein, this material enters the nasal cavity, arrives at the cranial nerves and activates the brain.