The temperature dependence of the heat capacity for partially crystalline polyketone derived from carbon monoxide with ethylene and butene-1 (the butane units content is 14.6 mol %) was studied over the range 6–520 K by the methods of precision adiabatic vacuum calorimetry and differential scanning calorimetry. Thermodynamic characteristics of the glass transition and glassy state and melting characteristics were determined. The standard thermodynamic functions, namely, and , were calculated for the temperature range from T → 0 to 400 K, based on the experimental data. Thermal stability temperature for polyketone (520 K) has been specified by the thermogravimetry methodThe temperature dependence of the heat capacity for partially crystalline polyketone derived from carbon monoxide with ethylene and butene-1 (the butane units content is 14.6 mol %) was studied over the range 6–520 K by the methods of precision adiabatic vacuum calorimetry and differential scanning calorimetry. Thermodynamic characteristics of the glass transition and glassy state and melting characteristics were determined. The standard thermodynamic functions, namely, and , were calculated for the temperature range from T → 0 to 400 K, based on the experimental data. Thermal stability temperature for polyketone (520 K) has been specified by the thermogravimetry method