The present invention relates to a novel catalyst which has a molecular sieving effect (or shape selectivity) and has excellent catalytic activity, and particularly to a catalyst which includes a core made of a zeolite particle having a particle size of not more than 10 μm and a zeolite layer covering the core, wherein as measured by X-ray photoelectron spectroscopy, an outermost surface of the catalyst has a silica/alumina molar ratio of not less than 800, the core made of the zeolite particle has an average silica/alumina molar ratio of not more than 300, and the zeolite layer has an aluminum concentration increasing inward from an outer surface of the catalyst.