Photoreflectivity, wavelength modulation spectroscopy and photoluminescence measurements of CuGaSe₂ are used to determine the exciton and band parameters as well as the energy band structure of CuGaSe₂ at photon energies higher than the fundamental band gap. The spectral dependences of the real ε₁ and imaginary ε₂ components of the complex dielectric function ε(E) = ε₁ (E) + iε₂(E) are calculated using the Kramers-Kronig relations. As a result, the energy band structure of CuGaSe₂ at photon energies higher than the fundamental band gap is derived from the analysis of the structures observed both in the ε (ω) and in the wavelength modulated reflectivity spectra.