Provided is a new catalyst structure for exhaust gas treatment including an upper catalyst layer and a lower catalyst layer, in which the catalyst structure can sufficiently exhibit functions as a three way catalyst while maintaining gas diffusibility. Proposed is a catalyst structure including a substrate, an upper catalyst layer, and a lower catalyst layer, the catalyst structure having a first peak or a second peak at a pore volume diameter of 10 nm to 50 nm and a pore volume diameter of 50 nm to 100 nm, respectively, in the logarithmic differential pore volume distribution analyzed by a mercury intrusion porosimeter.