EN
An optical pump - terahertz probe technique was used for measuring electron lifetime in various Ga_{1-x}Mn_xAs epitaxial layers with the subpicosecond temporal resolution. The measurements were performed on the samples with x up to 2%, which had large resistivities and were transparent in a THz frequency range. It has been found that an induced THz absorption relaxation is the fastest and electron lifetimes are the shortest for the samples with the smallest Mn content. For the samples with x=0.3% and x=2% this relaxation becomes much slower; its rate is comparable to the carrier recombination rate in Ga_{1-x}Mn_xAs substrate.