Titanium oxide ceramics were prepared using extrusion process and subsequent thermal treatment in two stages – in air atmosphere at 1150°C and than in vacuum at temperatures between 1200 and 1350°C. Influence of thermal treatment conditions on microstructure and electrical properties (thermopower, conductivity of semiconductor and electron activation energy) of obtained ceramics was investigated. It was confirmed that all samples treated in vacuum are n-type semiconductors. It was also found that the increase of temperature during sintering in vacuum leads to increased electrical conductivity, however, the highest thermopower values were obtained for samples thermally treated in vacuum at 1225°C. Electron activation energy (ΔE), calculated using dependence of conductivity of samples on temperature, was is in the range from 0.049 to 0.061 eV. The obtained products can be used as electrodes for water treatment technology based on photoelectrolysis.