a method and a device are for cooling the inflow area of the shaft of a steam turbine . according to the method and device , a partial mass flow m 1 is branched off upstream of a feed device that supplies the steam to the team turbine . the partial mass flow is cooled and then guided to the feed device , from where it is supplied to the steam turbine together with the remaining mass flow m 2 . the method and device allow for a simplified control and design of the turbine .