A gas leak detection device for identifying a gas leak in a test object, comprising a connector for the test object or for a test chamber accommodating the test object; a vacuum pump (16, 18) connected to the connector for evacuating the test object or test chamber; a gas detector connected to the vacuum pump (16, 18) and to the connector and configured for detection of a first test gas and for integral leak detection or for localizing leak detection of a gas leak in the test object according to the spraying principle during continuous operation of the vacuum pump (16, 18), a gas pressure sensor connected to the vacuum pump (16, 18) and to the connector and configured for integral measurement of the total pressure increase according to the pressure increase method and/or the partial pressure increase of at least one second test gas different from the first test gas according to the partial pressure increase method, and a blocking device configured for separating, in terms of vacuum, the gas pressure sensor and the connector from the vacuum pump (16, 18) when the test object is examined by means of the gas pressure sensor, characterized in that a gas conducting path connecting the connector to the vacuum pump (16, 18) comprises a booster pump, and the gas pressure sensor is arranged in the gas conducting path between the booster pump and the vacuum pump (16, 18) and thus downstream of the booster pump and upstream of the vacuum pump (16, 18) so as to measure, with the blocking device closed, the total pressure increase and/or the partial pressure increase of the second test gas in the gas conducting path downstream of the booster pump and upstream of the vacuum pump (16, 18) and/or of the gas detector, using the gas pressure sensor. a connector for the test object or for a test chamber accommodating the test object; a vacuum pump (16, 18) connected to the connector for evacuating the test object or test chamber; a gas detector connected to the vacuum pump (16, 18) and to the connector and configured for detection of a first test gas and for integral leak detection or for localizing leak detection of a gas leak in the test object according to the spraying principle during continuous operation of the vacuum pump (16, 18), a gas pressure sensor connected to the vacuum pump (16, 18) and to the connector and configured for integral measurement of the total pressure increase according to the pressure increase method and/or the partial pressure increase of at least one second test gas different from the first test gas according to the partial pressure increase method, and a blocking device configured for separating, in terms of vacuum, the gas pressure sensor and the connector from the vacuum pump (16, 18) when the test object is examined by means of the gas pressure sensor, characterized in that a gas conducting path connecting the connector to the vacuum pump (16, 18) comprises a booster pump, and the gas pressure sensor is arranged in the gas conducting path between the booster pump and the vacuum pump (16, 18) and thus downstream of the booster pump and upstream of the vacuum pump (16, 18) so as to measure, with the blocking device closed, the total pressure increase and/or the partial pressure increase of the second test gas in the gas conducting path downstream of the booster pump and upstream of the vacuum pump (16, 18) and/or of the gas detector, using the gas pressure sensor.