Examination of Ga₂O₃ as solid-state nuclear detector was carried out. Ga₂O₃ is a wide bandgap material with beneficial physical properties that enable its application in harsh environmental conditions, such as elevated temperature or strong electromagnetic field; therefore, Ga₂O₃ could become a competitor of diamond and 4H silicon-carbide nuclear detectors. Furthermore, because of its high oxygen content the new detector material can play an important role in the field of reactor research due to the ¹⁶O(n, α)13C reaction. Monocrystalline β-Ga₂O₃ samples were investigated under 14 MeV fast neutron irradiation. On unintentionally doped semiconducting and Mg-doped insulating crystals metallic films were deposited in order to form the contact electrodes for biasing and to collect the electron-hole pairs generated by secondary particles after nuclear interactions between neutrons and the nuclei of the Ga₂O₃ crystal. The Mg-doped sample could be operated from zero up to more than 1000 V biasing level. The recorded electric signal and energy histograms were investigated.