A method of manufacturing a hollow component, such as a fan blade for a gas turbine engine, includes the steps of: (a) providing first and second panels and a membrane; (b) providing a stop-off material on at least one of the first and second panels and the membrane to define regions where no diffusion bonding is to take place; (c) assembling the panels and the membrane together so the membrane is between the panels; (d) diffusion bonding the panels and the membrane together. The method is such that when assembled in step (c) the membrane does not extend to at least one edge of the first and second panels, so that in that region the first and second panels are diffusion bonded directly to each other.