A method of manufacturing a hollow fan blade for a gas turbine engine using diffusion welding and superplastic forming, said blade consisting of titanium alloy skins and a core in the form of stiffening ribs, wherein the method comprising: assembling preforms of the skins (1, 2) and the core into a stack; preliminarily applying stop-off material in a predetermined screen pattern to areas where surfaces of the skin and core preforms come into contact, but are not to be bonded at diffusion welding, including a collector zone; also providing the skin preforms with a groove (9, 10) and the core preform with a slot for mounting at least one tube; sealing the stack along edges with the exception of where the at least one tube is to be mounted; mounting a tube and connecting it to the collector zone; removing oxygen and binder of the stop-off material from cavities of the stack; fully sealing the stack; heating the stack, and diffusion welding the preforms in predetermined areas (13, 14), also along an entrance edge, an exit edge and a peripheral edge, to produce an integral structural preform; giving an airfoil shape to the integral structural preform; carrying out superplastic forming by supplying working fluid into cavities between the skin and core preforms using also at least one tube, said method characterized in that the collector zone is disposed on the side of the stack, which corresponds to the peripheral edge of the blade; and, for mounting one or more tubes for supplying the working fluid at superplastic forming, the groove in the skin preforms and the slot in the core preform are provided at a distance from the outer boundary of the entrance edge or exit edge less than L/3, where L is the length of the blade chord along the peripheral edge. assembling preforms of the skins (1, 2) and the core into a stack; preliminarily applying stop-off material in a predetermined screen pattern to areas where surfaces of the skin and core preforms come into contact, but are not to be bonded at diffusion welding, including a collector zone; also providing the skin preforms with a groove (9, 10) and the core preform with a slot for mounting at least one tube; sealing the stack along edges with the exception of where the at least one tube is to be mounted; mounting a tube and connecting it to the collector zone; removing oxygen and binder of the stop-off material from cavities of the stack; fully sealing the stack; heating the stack, and diffusion welding the preforms in predetermined areas (13, 14), also along an entrance edge, an exit edge and a peripheral edge, to produce an integral structural preform; giving an airfoil shape to the integral structural preform; carrying out superplastic forming by supplying working fluid into cavities between the skin and core preforms using also at least one tube, said method characterized in that the collector zone is disposed on the side of the stack, which corresponds to the peripheral edge of the blade; and, for mounting one or more tubes for supplying the working fluid at superplastic forming, the groove in the skin preforms and the slot in the core preform are provided at a distance from the outer boundary of the entrance edge or exit edge less than L/3, where L is the length of the blade chord along the peripheral edge.