(EN) The purpose of the present invention is to provide: a Co-based alloy product having mechanical properties that are equivalent or superior to those of precipitation-hardened Ni-based alloy materials; and a method for producing the Co-based alloy product. The Co-based alloy product according to the present invention has a chemical composition which contains 0.08 to 0.25% by mass of C, 0.1% by mass or less of B and 10 to 30% by mass of Cr, also contains 5% by mass or less of Fe and 30% by mass or less of Ni wherein the total amount of Fe and Ni is 30% by mass or less, also contains W and/or Mo wherein the total amount of W and Mo is 5 to 12% by mass inclusive, also contains at least one element selected from Ti, Zr, Hf, V, Nb and Ta in a total amount of 0.5 to 2% by mass inclusive, and also contains 0.5% by mass or less of Si, 0.5% by mass or less of Mn and 0.003 to 0.04% by mass of N, with the remainder made up by Co and impurities, wherein the impurities contain 0.5% by mass or less of Al and 0.04% by mass or less of O. The product is characterized in that the product is a polycrystal body of matrix phase crystals, post-segregation cells which have an average size of 0.13 to 2 µm inclusive are formed in crystal grains of the polycrystal body, and MC-type carbide phase grains each containing the Ti, the Zr, the Hf, the V, the Nb and/or the Ta are dispersed and deposited on the boundaries of the post-segregation cells.
