Photoluminescence of two diamond samples excited by radiation of a KrCl laser with a spectral maximum at the wavelength λ ~ 222 nm is investigated. Radiative recombination bands of free excitons and electron-hole liquid are simultaneously observed in the integrated difference photoluminescence spectra of a diamond sample synthesized by chemical vapor deposition method during cooling by liquid nitrogen. The N3 electronic vibrational system and the band-A of luminescence are observed in the integrated difference photoluminescence spectra of a natural sample of diamond of IIa type under analogous conditions. Temperature dependences of the spectral intensity of photoluminescence bands of diamond samples in the temperature range T = 80–300 K are determined.