Copper-supported zeolite and exhaust-gas purification treatment catalyst containing said zeolite

This invention provides a copper-supported SAPO which has not only excellent high-temperature steam durability of a silicoaluminophosphate zeolite (SAPO) but also excellent low-temperature steam durability. Provided is a copper-supported zeolite in which copper is supported by a zeolite, the zeolite containing in the skeleton structure thereof at least a silicon atom, a phosphorus atom, and an aluminium atom, wherein the copper-supported zeolite satisfies (1)-(3) below. (1) The copper-supported amount (in terms of copper atoms) is 1.5-3.5 wt%. (2) The UV-Vis-NIR absorption intensity ratio obtained by the following formula (I) is less than 0.35: Intensity(22000 cm -1 )/Intensity(12500 cm -1 ) ... (I). (3) The silicon atom content satisfies the following formula (II): 0.07≤x≤0.11 ... (II), wherein x is a molar ratio of the silicon atoms with respect to the total amount of the silicon atoms, the aluminium atoms, and the phosphorus atoms in the zeolite skeleton structure.