This face mask includes a right side sheet and a left side sheet which are mutually enantiomorphic. On a right side sheet and a left side sheet, a thermoplastic adhesive material is applied to the inner sides of ranges which include front edge strip portions which, during use, oppose the median line of the users face the right side sheet and the left side sheet are then laid together overlapping their inner sides and heat is applied to areas of these front edge portions other than portions which, during use, oppose the nostrils and the mouth of the user, so that thereby the right side sheet and the left side sheet are joined together. By then opening out the right side sheet and the left side sheet in the direction to separate them, this face mask is caused to assume a three dimensional shape over its entire surface.
