[en] Fission chambers of parallel-plate type are provided to measure the central fission rates of ²³⁷Np, ²³⁸Pu, ²³⁹Pu, ²⁴²Pu, ²⁴¹Am, ²⁴³Am, ²⁴⁴Cm and ²³⁵U in a series of the cores in fast critical assemblies FCA. The chamber consists of the body made of a thin stainless steel wall, the collector of a circular disk and the electrodeposited source with a platinum disk of 0.2 mm thick. The gas filled in the chamber is a mixture of 97% Ar and 3% N₂ at 1 atmosphere pressure. The weights of deposit are adjusted from strength of α-specific activity for each nuclide. In the test using FCA, characteristics of low α pile-up are obtained for all chambers prepared. The determination of masses by α-assay, correction for fissile impurities and the sensitivity of chambers are examined for the individual chamber. It is shown from the experiment that the actinide fission rates can be measured within errors of +-2 -- +-5%. From this result, it concludes that the present chambers are effectively used for the experimental evaluation of nuclear cross sections for the actinide nuclides. (author)