Photoluminescence (PL) has been used to study defects introduced by 1‐MeV‐electron irradiation in cubic silicon carbide (3C‐SiC) films epitaxially grown on Si substrates by means of chemical vapor deposition. A dominant PL line of 1.913 eV observed in 3C‐SiC irradiated with electrons was found to disappear at annealing stages of ≊100 and 700 °C. The annealing stages of the 1.913 eV PL center and its fraction annealed at each annealing stage were in good agreement with those obtained for theT1 electron spin resonance center, which is attributed to isolated vacancies at silicon sublattice sites [H. Itoh, M. Yoshikawa, I. Nashiyama, S. Misawa, H. Okumura, and S. Yoshida, IEEE Trans. Nucl. Sci.NS‐37, 1732 (1990)]. This result indicates that the 1.913 eV PL line arises from silicon vacancies in 3C‐SiC. The characteristics of other PL lines induced in 3C‐SiC epilayers by irradiation are also discussed. ©1995 American Institute of Physics.