ELECTRODE CATALYST LAYER USING CATALYST, MEMBRANE ELECTRODE ASSEMBLY, AND FUEL CELL

[Object] Provided is a catalyst having an excellent gas transportability. [Solving Means] Disclosed is a catalyst including a catalyst metal and a support, wherein the catalyst includes pores having a radius of 1 nm or more and less than 5 nm, a pore volume of the pores is 0.8 cc/g support or more, and the catalyst metal has a specific surface area of 30 m 2 /g support or less.