An impeller of a centrifugal includes, a plurality of full blades provided from the fluid inlet part to the fluid outlet part of the impeller; a plurality of splitter blades provided on the hub surface, wherein the geometry of a flow entering part of the splitter blade is compatible with the complicated flow inside the compressor so that the evenly distributed flow rate distribution, the increased pressure ratio and the enhanced efficiency are achieved. The leading edge blade angle θ in the tip end part of the flow entering front-end-part of the splitter blade 7 in the area of the higher height level from the hub surface is further inclined smoothly toward the blade suction surface side Sb of the full blade 5 in comparison with the inclination standard curve, the increased inclination angle becoming smoothly greater in response to the increase of the height level.