pressure at rotation of the wind turbine the distortion is absorbed by the connection part 12 a with flexible structure for this reason the stress applied to the structural beam 10 by the distortion of the hub 5 is suppressed in comparison with a strong member with rigid structure having enough large strength to prevent influence of the distortion of the hub 5 this structure can support various equipment in the hub 5 with a lighter weight fig1 to fig3 illustrate the example of an upwind type wind turbine in which one end of the structural beam 10 is rigidly connected at the rear part of the hub 5 leeward side and the other end of the structural beam 10 is flexibly connected to the front part of the hub 5 windward side however for applying to wind turbines having other structures the supporting structure shown in fig4 in which one end is rigidly connected and the other end is flexibly connected can achieve similar effects for example even when the structural beam 10 is disposed in a longitudinal direction as a direction diagonal to the direction of back and forth of the hub 5 as long as one end and the other end of the structural beam 10 are rigidly connected to and flexibly connected to the hub 5 respectively the stress applied to the structural beam 10 can be suppressed also.