When various materials are used as radiators for Cherenkov detectors registering electron fluxes with energies of tens to hundreds of keV, cathodoluminescence negatively affects the useful signal. Therefore, in the process of creating Cherenkov detectors, the search for materials with a low level of the cathodoluminescence is important. In this paper, the spectral and amplitude-time characteristics of the yttrium sesquioxide ceramics glow under irradiation with an electron beam with electron energy up to ~ 350 keV are experimentally studied. The experimental spectrum of the ceramics glow is compared with the calculated spectrum of Cherenkov radiation. It is shown that the main part of the ceramics radiation energy belongs to Cherenkov radiation, and the cathodoluminescence level is low. The conclusion on the suitability of yttrium sesquioxide ceramics as a material for radiators of Cherenkov detectors is made.