The invention relates to a gas turbine group (1, 2, 3) equipped with at least one cooling air system (20, 21). Orifices (22, 23) serving as throttle locations are placed in the cooling air lines in order to regulate the nominal cooling air mass flow in a defined manner. Bypass lines (24) are arranged parallel to the orifices in the cooling air way. Means (25) for regulating a bypass mass flow are placed in said bypass lines. This enables the cooling air mass flow to be varied without directly acting upon the main cooling air flow.
