The heat capacity measurements of the crystalline phosphate CsMnPO4 with a beta-tridymite structure were performed between T = (5 and 650) K. Phase transitions were found at temperatures (6.9 and 127) K. They correspond to the order-disorder transition and the transition between monoclinic and orthorhombic modifications of CsMnPO4, respectively. Thermodynamic functions C-p,m(0)/R, Delta H-T(0)m(0)/RT, Delta S-T(0)m(0)/R and Phi(0)(m)/R were calculated over the range of T = (0 to 650) K from experimental values. The temperature dependence of the magnetic susceptibility of CsMnPO4 crystalline phosphate was studied over the temperature range from (2 to 300) K. (C) 2014 Elsevier Ltd. All rights reserved.