The linear optical, luminescence and electronic properties of La2Be2O5 (BLO) single crystals doped with Ce or Eu, were determined using optical absorption and luminescence spectroscopy techniques. On the basis of the obtained data, the locations of 4f and 5d energy levels for trivalent Ce3+ and Eu3+ impurity ions, and the energy thresholds for 4f→5d and charge transfer transitions were determined for BLO single crystal. The expected positions of the ground states of the 4fn and 4fn−15d levels of trivalent lanthanide ions as well as the 4fn+1 and 4fn5d levels of divalent ions were calculated for all the lanthanide ions in BLO host crystal.