This invention relates to a radial blade wheel comprising a first (1,1′) and a second (2,2′) end plate arranged at a mutual distance from each other, the first end plate having an opening (6) which allows inflow to the radial blade wheel, and blades (3) arranged between the first and the second end plate. To achieve optimal efficiency for the radial blade wheel, the radial blade wheel comprises an inner part with blades, in which curvature (R1) of the blades (3) is shaped to bring motion energy to the flowing particles while the radial blade wheel is rotating, and an outer part with blades, in which curvature (R2) of the blades (3) is shaped not to bring motion energy to the flowing particles while the radial blade wheel is rotating.