Patent ID: 8251065

Claim:
A four-sided dustproof mask, comprising: an upper filter adapted to surround a wearer's nose area; a lower filter adapted to surround the wearer's chin area; a protruded center filter adapted to attach the upper filter and the lower filter thereto in such a manner as to make the both ends of the upper filter and the lower filter correspond to center points formed at the both ends of a curved folding line dividing the protruded center filter into a top portion and a bottom portion, the curved folding line having at least two straight line portions, each straight line portion having a predetermined length and protrudedly extending, from one of the center points, whereby while the upper filter and the lower filter are being developed, the protruded center filter is protruded to a dome-like shape; and at least two curved band-attaching parts protruding from the center filter and configured to attach the dustproof mask to one or more ear bands.