Clamping device for storing and transporting a wind turbine blade comprising: a first structure and a second structure adapted to abut onto opposite sides (102, 104) of said wind turbine blade; a clamping force adjustment device permitting adjustment of the magnitude of the clamping force exerted by said first structure and said second structure onto said wind turbine blade; wherein said clamping device comprises: an elastic member arranged between said first structure and said second structure so as to apply to said first structure and said second structure an elastic force with a magnitude having a predetermined and univocal dependency on the amount of deflection of said elastic member with respect to a characteristic rest length, the magnitude of said clamping force being proportional to the magnitude of said elastic force; and a biasing mechanism adapted to deflect said elastic member, so as to permit adjustment of the magnitude of said elastic force, and said first structure comprises a first end portion adapted to be rotatably fixed to an end portion of said second structure and said first structure also comprises a second end portion opposite said first end portion, the position of said second end portion of said first structure with respect to said second structure being adjustable, wherein said biasing mechanism comprises at least one fastening member having a head adapted to abut onto an end portion of said elastic member, the distance of said head from said second structure being adjustable in such a way that the amount of compression of said elastic member increases as the distance of said head from said second structure is reduced. a first structure and a second structure adapted to abut onto opposite sides (102, 104) of said wind turbine blade; a clamping force adjustment device permitting adjustment of the magnitude of the clamping force exerted by said first structure and said second structure onto said wind turbine blade; an elastic member arranged between said first structure and said second structure so as to apply to said first structure and said second structure an elastic force with a magnitude having a predetermined and univocal dependency on the amount of deflection of said elastic member with respect to a characteristic rest length, the magnitude of said clamping force being proportional to the magnitude of said elastic force; and a biasing mechanism adapted to deflect said elastic member, so as to permit adjustment of the magnitude of said elastic force, and said first structure comprises a first end portion adapted to be rotatably fixed to an end portion of said second structure and said first structure also comprises a second end portion opposite said first end portion, the position of said second end portion of said first structure with respect to said second structure being adjustable, wherein said biasing mechanism comprises at least one fastening member having a head adapted to abut onto an end portion of said elastic member, the distance of said head from said second structure being adjustable in such a way that the amount of compression of said elastic member increases as the distance of said head from said second structure is reduced.