Annealing of 2.2 MeV electron irradiated 4H-SiC epilayer and bulk 4H-SiC was investigated by means of positron annihilation spectroscopy. The concentration of N was 5x10(16) cm(-3) in the epilayer and ∼ 10(18) cm(-3) in the bulk. Annealing was found to be independent of N concentration up to the temperature of 1450 ° C, at which temperature all radiation-produced defects detectable by positrons were annealed.