The present invention specifies the physical property valves of a catalytic layer correlating with the performance of a fuel cell, and provides the catalytic layer having the physical proper values and a fuel cell. Specifically, in a fuel cell having a membrane-electrode assembly provided with a catalytic layer 13 on each side of an electrolyte membrane 10, an electrode powder constituting the catalytic layer 13 shall have an amount of adsorbed water vapor in a range of 52 to 70 cm3(STP)/g by a value measured when the water-vapor partial pressure is 0.6, which is determined from the adsorption isotherm of water. The fuel cell having the catalytic layer with the use of the electrode powder having the amount of adsorbed water vapor in this range has the output performance of 0.6 A/cm2 or higher by current density at 0.6 V, in a less humidified condition and a more humidified condition.