[Object] Provided is a catalyst having excellent gas transportability.[Solving Means] Disclosed is a catalyst comprising a catalyst support and a catalyst metal supported on the catalyst support, wherein the catalyst includes pores having a radius of less than 1 nm and pores having a radius of 1 nm or more, wherein a pore volume of the pores having a radius of less than 1 nm is 0.3 cc/g support or more or a mode radius of a pore distribution of the pores having a radius of less than 1 nm is 0.3 nm or more and less than 1 nm, and wherein the catalyst metal is supported inside the pores having a radius of 1 nm or more.