A process and to a device for protecting a turbocompressor from operating in the unstable working range by means of a blow-off device, wherein a control parameter is determined from measured values for the compressor flow, the compressor final pressure and the temperature measurement, as well as from preset or presettable desired values, and controlled opening of the blow-off fittings is performed by a pump surge limiter by means of a pneumatic actuating device each on the basis of the said control parameter. The measured values for the temperature, flow and pressure entered into the pump surge limiter are coupled with a dynamic blow-off line. The blow-off fittings are operated in sequence, and the control signals for the quick opening of the blow-off fittings are first sent to a small blow-off fitting, and then to a large blow-off fitting after the opening of the small blow-off fitting. In cooperation with the dynamic blow-off line, the pump surge limiter provides for continuous control, i.e., a continuous adjustment of the blow-off fittings as a function of the location of the working point in the characteristic diagram of the turbocompressor.