Vacancies on silicon and carbon sublattices of hexagonal silicon carbide (6H-SiC) have been selectively induced by low temperature electron irradiation and specifically identified by a combination of two positron annihilation techniques, by the novel two-detector Doppler broadening techniques and by the well-known positron lifetime technique. The vacancies induced by irradiation with electrons of low energies from 230 to 350 keV exhibit a positron lifetime of 153 ps and could be attributed to carbon vacancies because they are characterized by Si nearest neighbors. The vacancies which trap positrons after 500 keV electron irradiation are found to be surrounded by carbon nearest neighbor atoms and are, therefore, located on the Si sublattice with a positron lifetime of 176 ps. The energy of electrons between 1.0 to 3.0 MeV is enough for displace nearest neighbor silicon atoms by one electron. These divacancies exhibit positron lifetime of 210 ps.