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The techniques of capacitance spectroscopy are used to measure directly electron and hole capture cross-sections of deep levels in a neutral material at zero electric field and in the depletion layer with a strong electric field. The data show that if at zero electric field the electron capture crosssections onto the centers are thermally activated and described by the theory of nonradiative multiphonon capture, then in a strong electric field (P z lo4 V/cm) the capture cross-sections increase to the limiting large value (a Y lOV14 to 10-12 cmz) and are only little dependent on temperature. It is shown that an electric field causes a simultaneous increase of the electron and hole capture cross-sections of the level EL2 by five orders of magnitude at low temperatures (27 Y Y 90 K).

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