The present paper is devoted to experimental and quantum chemical investigation of thermodynamic properties of C₆₀CHCOOH derivative. As a result, we presented smoothed C_p,m°(T) values in the temperature range from T → 0 K to T = 320 K and the values of standard thermodynamic functions: entropy S_m°, [H_m°(T) − H_m°(0)] and [Φ_m°(T) − Φ_m°(0)]. Additionally, we calculated the molar third law, S_m°, and the molar entropy of formation, Δ_fS_m°, of the C₆₀CHCOOH derivative in crystalline state (T = 298.15 K). The results of DFT-calculation of isobaric heat capacities and calculated ¹³C NMR spectrum of carboxylated fullerene are in a good agreement with experimental data.