An air-bag integrally formed by hollow weaving, the air-bag comprising a main chamber that inflates, and a non-inflating portion, wherein the main chamber has a two-layer structure comprising a first fabric layer and a second fabric layer, the main chamber includes an opening continuously formed by the hollow weaving and communicating with an outside, or a communication part communicating with an auxiliary chamber in the air-bag, wherein the air-bag has a structure where a plurality of filaments organizing the first fabric layer extend separately from the first fabric layer in the opening or the communication part to either the non-inflating portion or to the first or second fabric layer and not to the non-inflating portion, to form a first yarn, and the air-bag has a structure where a plurality of filaments organizing the second fabric layer extend separately from the second fabric layer in the opening or the communication part to either the non-inflating portion or to the first or second fabric layer and not to the non-inflating portion, to form a second yarn, characterized in that the first fabric layer comprises one or more first float yarns once separating from the first fabric layer and returning to the first fabric layer, in that the second fabric layer comprises one or more second float yarns once separating from the second fabric layer and returning to the second fabric layer, in that the first yarn is, in order seen from the opening or the communication part, caught on the one or more second float yarns, or constitutes a woven organization with the second float yarns, and is subsequently caught on the one or more first float yarns, or constitutes a woven organization with the first float yarns, the structure being repeated at least once, in that he second yarn is, in order seen from the opening or the communication part, caught on the one or more first float yarns, or constitutes a woven organization with the first float yarns, and is subsequently caught on the one or more second float yarns, or constitutes a woven organization with the second float yarns, the structure being repeated at least once, in that during air-bag inflation, the first yarn and the second yarn are pulled by the first float yarns and the second float yarns to apply tension, and operate to close the opening or the communication part, and when making contact with an occupant, by deformation of the air-bag due to the contact, the first yarn and the second yarn are loosened, and the opening or the communication part is opened to release gas from the main chamber. the air-bag comprising a main chamber that inflates, and a non-inflating portion, wherein the main chamber has a two-layer structure comprising a first fabric layer and a second fabric layer, the main chamber includes an opening continuously formed by the hollow weaving and communicating with an outside, or a communication part communicating with an auxiliary chamber in the air-bag, wherein the air-bag has a structure where a plurality of filaments organizing the first fabric layer extend separately from the first fabric layer in the opening or the communication part to either the non-inflating portion or to the first or second fabric layer and not to the non-inflating portion, to form a first yarn, and the air-bag has a structure where a plurality of filaments organizing the second fabric layer extend separately from the second fabric layer in the opening or the communication part to either the non-inflating portion or to the first or second fabric layer and not to the non-inflating portion, to form a second yarn, characterized in that the first fabric layer comprises one or more first float yarns once separating from the first fabric layer and returning to the first fabric layer, in that the second fabric layer comprises one or more second float yarns once separating from the second fabric layer and returning to the second fabric layer, in that the first yarn is, in order seen from the opening or the communication part, caught on the one or more second float yarns, or constitutes a woven organization with the second float yarns, and is subsequently caught on the one or more first float yarns, or constitutes a woven organization with the first float yarns, the structure being repeated at least once, in that he second yarn is, in order seen from the opening or the communication part, caught on the one or more first float yarns, or constitutes a woven organization with the first float yarns, and is subsequently caught on the one or more second float yarns, or constitutes a woven organization with the second float yarns, the structure being repeated at least once, in that during air-bag inflation, the first yarn and the second yarn are pulled by the first float yarns and the second float yarns to apply tension, and operate to close the opening or the communication part, and when making contact with an occupant, by deformation of the air-bag due to the contact, the first yarn and the second yarn are loosened, and the opening or the communication part is opened to release gas from the main chamber.