In the present work temperature dependence of heat capacity of vitamin wB(2) (riboflavin) has been measured for the first time in the range from 6 to 322 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B-2, namely, the heat capacity, enthalpy H degrees(T)-H degrees(0), entropy S degrees(T)-S degrees(0) and Gibbs function G'(T)-H degrees(0) have been determined for the range from T -> 0 to 322 K. The value of the fractal dimension Din the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. In a calorimeter with a static bomb and an isothermal shield, the energy of combustion of the riboflavin has been measured at 298.15 K. The enthalpy of combustion Delta H-c degrees and the thermodynamic parameters Delta H-f degrees, Delta S-f degrees, Delta(f)G degrees and of reaction of formation of the riboflavin from simple substances at T=298.15K and p=0.1 MPa have been calculated. Published by Elsevier B.V.