Modes of precision triggering of a high-pressure nitrogen spark gap at voltages of some tens of kilovolts have been investigated. The spark gap was triggered by a high-current electron beam. Experimentally, a total jitter no more than 25 ps relative to the leading edge of the beam-accelerating voltage pulse was attained. The time for which the spark gap was in the induced conduction state corresponds to the duration of the triggering beam current.