To provide a mask which reduces a gap between the mask body and the nose and the cheek, presents a slipping off from occurring, and also, prevents the fogging of spectacles of a spectacle user from occurring.

The upper edge and both side edges of a nose engaging section 12 are fixed to the upper edge and both side edges of the mask body 11. The lower edge of the nose engaging section is not fixed, and is engaged with the nose by folding back. In the nose engaging section, a ventilation shut-off member is built in, and breath is prevented from leaking upward from the nose engaging section. By this constitution, a slipping off is prevented from occurring, and also, the fogging of spectacles of a spectacle user is prevented from occurring.