The present invention relates to a gas mask comprising: a rubber material face mask, which is worn on the face for protecting the face against toxic substances, and which includes a purification container connection hole to which a purification container is connected, a lens hole in which a lens is installed, an exhaust hole in which an exhaust unit for exhausting inside air is installed, and a hook which protrudes toward a back direction a buckle onto one side of which the hook on the face mask is coupled so as to be separable a back head cover, which comprises a coupling lace which is coupled to the other side of the buckle so as to be separable, for covering the back head of the wearer by connecting to the back side of the face mask by means of the buckle when the coupling lace is coupled to the buckle a headscarf, which is provided with an exposure hole through which the front surface of the face mask provided with the connection hole, the lens hole, and the exhaust hole, is exposed, wherein the periphery of the exposure hole is connected to the edge of the front surface of the face mask to shield the head portion of the wearer and a connector for partially connecting the periphery of the exposure hole, which is formed on the headscarf, to the face mask. In the present invention, the periphery of the exposure hole, which is formed on the headscarf, is connected to the face mask by means of the connector so that the headscarf is securely and quickly connected to the face mask, thereby protecting the head of the wearer from toxic substances.La présente invention concerne un masque à gaz comprenant: un masque facial en caoutchouc, porté sur le visage pour protéger le visage contre les substances toxiques et comprenant un orifice de raccordement de contenant de purification auquel est raccordé un contenant de purification, un trou de lentille dans lequel est montée une lentille, un trou de dégagement dans lequel est montée une unité de dégagement pour le dégagement
