마스크의 형상을 위해 제공 될 수있는 본 발명의 일 실시 예에 따른 쉘 구조는, 가장자리를 형성하는 원주 방향 부 및 원주 부분과 일체로 형성된 아치 형상 곡면 부가
A shell structure according to an embodiment of the present disclosure, which may be provided for a shape of a mask, includes a circumferential part forming an edge, and an arch-shaped curved part integrally formed with the circumferential part at an inner side of the circumferential part, wherein a groove part is formed along a vertical central line of the curved part at a rear surface of the curved part such that the curved part is formed to be foldable about the groove part as a central line.