To provide sulfuric acid-modified Y-type zeolite having a crystal structure characteristic of the Y-type zeolite and having an increased acid amount.SOLUTION: The sulfuric acid-modified Y-type zeolite has a SiO/AlOmolar ratio in a range of 3.0 to 6.0 and has a crystal structure characteristic of the Y-type zeolite. At the same time, after the sulfuric acid-modified Y-type zeolite is dried at 110°C for 1 hour, 5 g is weighed and this is made into a 5% slurry using 95 g of pure water at 25°C. After stirring for 18 hours, this slurry was filtered. Subsequently, operation of passing 50 g of pure water through the filtered solid content is performed three times, and the washed solid content obtained is dried at 110°C for 1 hour. Thereafter, a SO/AlOmolar ratio is measured to be in a range of not less than 0.00050.SELECTED DRAWING: None【課題】Ｙ型ゼオライトに特有の結晶構造を有しており、増大した酸量を有する硫酸改質Ｙ型ゼオライトを提供する。【解決手段】ＳｉＯ２／Ａｌ２Ｏ３モル比が３．０～６．０の範囲にあり且つＹ型ゼオライトに特有の結晶構造を有していると共に、１１０℃で１時間乾燥させた後、５ｇを量り取り、２５℃の純水９５ｇを用いて５％スラリーとし、これを１８時間攪拌した後に濾過し、次いで濾過固形分に５０ｇの純水を通す操作を３回行い、得られた洗浄固形分を１１０℃で１時間乾燥した後に測定して、ＳＯ３／Ａｌ２Ｏ３モル比が０．０００５０以上の範囲にあることを特徴とする。【選択図】なし
