An electrode catalyst support, capable of improving the power of a fuel cell, and an electrode catalyst and a solid polymer fuel cell using the same.
Provided is carbon black wherein pores which are at most 6 nm in pore diameter have a cumulative pore volume of less than 0.25 cm3/g, a specific surface area by BET is 500 to 900 m2/g, and a volatile matter content is 1.0 to 10.0%. Also provided are an electrode catalyst for a fuel cell comprising a support which includes this carbon black, and a solid polymer fuel cell having the electrode catalyst.