A process and device for controlling the heating of the glow plugs of a diesel engine. To be able to take into consideration the thermal behavior of the glow plugs while controlling the current supply of the glow plugs (3) of a diesel engine, the thermal behavior of the glow plugs (3) is emulated via a physical model. Formed on the corresponding output signal of the model (4), which is proportional to the glow plug temperature, is a reference signal, which as a control value, lies on the electronic control (12) controlling the heating flow of the glow plugs (3), which accordingly controls the heating of the glow plugs (3) using the actual glow plug temperature determined from emulation.