Low temperature heat capacity of erbium phosphate ErPO4 was measured by relaxation calorimetry (2-35 K) and adiabatic calorimetry (5-345 K). High-temperature enthalpies of this substance were studied by drop calorimetry in the region of 357-1575 K. Smoothed thermodynamic properties (heat capacity, entropy, enthalpy change and derived Gibbs energy) were calculated in the range of 0-1600 K. Gibbs energy of formation of ErPO4 was estimated using the standard entropy S-0(298.15 K) from this work: Delta(f)G(0) (ErPO4, 298.15 K) = -1855.3 +/- 2.1 kJ mol(-1). The Schottky heat capacity anomaly was observed in the range from 2 to 300 K. (C) 2012 Published by Elsevier B.V.