Abstract: Fluid diffuser and method for constructing the same are disclosed. The fluid diffuser including a pair of disks having opposite, facing surfaces of revolution with a common axis of symmetry for defining a fluid flow path. The cross-section of the fluid flow path normal to the direction of flow is constructed and arranged so that the cross-section varies continuously with the radial distance from the common axis of symmetry so as to provide uniform fluid flow velocities in plane and in section at the periphery of the diffuser. The method for manufacturing the fluid diffuser includes rigidly fastening together a plurality of elements shaped to conform to the shape of the inner surface of the diffuser so as to form a skeletal frame. Thereafter, a unitary sheet of resilient material is stretched on the frame to cover the same thus causing the material to define the desired surface, the stretch material being fastened by suitable means to the frame.