The main aim of this work was to learn more about properties of iron phosphate glasses and to investigate the structural properties of iron phosphate glasses of molar composition \(40Fe_{2}O_3-60P_2O_5\). The first part of the diploma thesis deals with glasses in general; their historical development, types and possible applications. Also, description of methods (X-ray diffraction and electron microscopy) and devices used in this diploma work is given in this section.Ferrous phosphate glases are described in the second part of the work and the results of our study of molar composition \(40Fe_2O_3-60P_2O_5\) are given. We heated \(40Fe_2O_3-60P_2O_5\) at different temperatures ranging from \(530\, ^\circ\)C to \(800\, ^\circ\)C,during time periods of 1h, 6 h, 12 h, 24 and 48 h and monitored the influence of different procedures on formation of the crystal structure. Treatment at temperatures up to \(590\, ^\circ\)C (\(530\, ^\circ\)C, \(560\, ^\circ\)C i \(590\, ^\circ\)C)with shorter times (1 h and 6 h) resulted in the formation of amorphous structures, as expected for this type of glass. By increasing temperature and the heating time proportion of amorphous phase in structure decreased, wherein the long-term heating of the material to very high temperature (\(800\, ^\circ\)C i 48 h) resulted in its complete crystallization. In this way, assumption that crystallization depends of the temperature as well as of the heating time was confirmed. Further studies of this system, performed at Rudjer Boskovic Institute, Laboratory for Functional Materials revealed polaronic conductivity with an increase in electrical conductivity upon formation of two additional crystalline phases \((Fe_4(P_2O_7)_3\) and \(Fe(PO_3)_3)\) mostly due to higher concentration of the \(Fe^{2+}\)/\(Fe^{3+}\) ion pairs.