Abstract: Control device for a steam turbine having a high-pressure and a medium or low-pressure turbine part, includes a reheater, at least one live steam control valve disposed upstream of the high-pressure turbine part, at least one intercept control valve disposed upstream of the medium or low-pressure turbine part and downstream of the reheater, a control device having at least one turbine controller for simultaneously acting on the live steam control valve in accordance with a predetermined live steam valve characteristic and acting on the intercept control valve in accordance with a predetermined intercept valve characteristic, the live steam control valve and the intercept control valve having a normal characteristic correlation therebetween determining a correlation of high-pressure and medium or low-pressure steam mass flow, a limit detecting device associated with the high-pressure turbine part for responding when a predetermined thermal stress is reached in the high-pressure turbine part, and a positioning