In the thesis, the crystallizat ion effect on the electrical processes and the magnetic interactions in glass wit h composit ion 40Fe2O3-60P2O5(mol%) was investigated. Controlled crystallizat ion leads to partially and fully crystallized glasses. This glass exhibits the electronic conduct ion, as a result of electron hopping from Fe2+ to Fe3- ions, which is described by small polaron hopping model, whereas magnet ically belongs to the spin-glass. The influence of crystallizat ion temperature and t ime on structural changes, the appearance of crystalline phases, their interactions and influence on electrical transport and magnet ic properties have been invest igated. Various methods were used: DTA, XRPD, spectroscopy (Raman, Mössbauer and Impedance) together with magnetochemical measurements (VSM). Depending on crystallizat ion temperature and t ime, various phases occur in glass matrix such as: Fe3(P2 O7)2, Fe4(P2O7)3 and Fe(PO3). Total conduct ivit y decreases in the first stage of the crystallizat ion process and achieves its minimum. Wit h further increase of the crystallizat ion temperature, the electrical conduct ivit y rises as a result of an enhanced crystallinit y. Contribution of the each phase to the total conduct ivit y is determined. Magnetic measurements showed dominant antiferomagnet ic interactions in all samples but some weak ferromagnet ic interact ions were also present in crystallized samples.