for a flow medium a for example hot steam is formed by the shaft 43 the blading region 51 and the guide vane carrier 47 the inflow region 49 serving for supplying the flow medium a is delimited in the radial direction by an inflow casing 55 disposed upstream of the guide vane carrier 59 an outflow casing 57 is disposed downstream on the guide vane carrier 47 and delimits the outflow region 53 in the radial direction when the steam turbine 59 is in operation the flow medium a here a hot steam flows from the inflow region 49 into the blading region 51 where the flow medium a by expansion performs work and thereafter leaves the steam turbine 59 via the outflow region 53 the flow medium a is subsequently collected in a condenser not illustrated in any more detail in fig8 for the steam turbine 59 the condenser being located downstream of the outflow casing 57 when flowing through the blading region 51 the flow medium a expands and performs work on the moving blades 1 with the result that these are set in rotation the moving blades 1 of the low pressure steam turbine 51 are formed of at least in regions of the cellular material 5 as described in fig2 to 7 as a result the moving blades 1 have a lower density as compared with conventional.