This paper presents experimental and simulated isobaric heat capacities of the C₆₀(OH)₄₀ fullerenol in the temperature range from T = 0 to 320 K along with the values of standard thermodynamic functions: S_m°, [φ_m°(T) - φ_m°(0)], and [H_m°(T) - H_m°(0)]. Furthermore, the molar entropy of formation and the molar third law entropy of C₆₀(OH)₄₀ in the crystalline state at T = 298.15 K were calculated. The results of the simultaneous thermal analysis reveal that C₆₀(OH)₄₀ is stable up to 340 K, and further increase of temperature leads to the destruction of the fullerene derivative and the oxidation of the fullerene core.