The present invention is a catalyst for a solid polymer fuel cell including: catalyst particles of platinum, cobalt and manganese; and a carbon powder carrier supporting the catalyst particles, wherein the component ratio (molar ratio) of the platinum, cobalt and manganese of the catalyst particles is of Pt:Co:Mn=1:0.06 to 0.39:0.04 to 0.33, and wherein in an X-ray diffraction analysis of the catalyst particles, the peak intensity ratio of a Co—Mn alloy appearing around 2θ=27° is 0.15 or less on the basis of a main peak appearing around 2θ=40°. It is particularly preferred that the catalyst have a peak ratio of a peak of a CoPt3 alloy and an MnPt3 alloy appearing around 2θ=32° of 0.14 or more on the basis of a main peak.