An experimental analysis of the 3D velocity field of flow is very effective for the understanding of the physical significance of complex flow and for the practical design of fluid machinery. Under the currently circumstance, stereoscopic particle image velocimetry (SPIV) is one of the promising techniques for the experimental analysis. Although the development of algorithms and the feasibility studies of SPIV have been realized, the accumulation of techniques for applications leading to the design of practical fluid machineries or devices is not yet sufficient. To establish practical techniques for the experimental analysis of 3D flow in fluid machinery by SPIV, the detailed 3D analysis of flow using a utility model of multiblade fans used in automobile air-conditioning systems has been carried out. The stereo view camera arrangement and laser-light-sheet illumination for the complex shape of the fan and for the 3D flow through it have been investigated, and the visualization of experimental results for the understanding of the flow structure has also been discussed. The results obtained using the practical techniques applied in this experiment provide knowledge useful in the understanding of flow through the fan and in improving it.