A gas-adsorbing material may increase gas barrier properties for a target gas by reducing a gas-adsorption rate while maintaining gas-adsorption performance. A vacuum insulation material may use the gas-adsorbing material. The gas-adsorbing material may include a gas-adsorbing composition including a copper ion exchanged ZSM-5-type zeolite having a silica to alumina ratio ranging from about 10 to 50 in a framework of zeolite. A ratio of dealuminization of the ZSM-5-type zeolite is at least about 15%, and the gas-adsorbing material is capable of adsorbing at least nitrogen. Furthermore, the gas-adsorbing material may include a calcinated body of a compressed article comprising a gas-adsorbing composition including a copper ion exchanged ZSM-5-type zeolite having a silica to alumina ratio ranging from about 10 to 50 in a framework of zeolite (where a ratio of dealuminization of the ZSM-5-type zeolite is at least about 15%) and a moisture-absorbing material.