A new model turbo-fan engine for small aircrafts is being developed as a national project. Multiple slot cooling configuration that is a new cooling structure of a turbine blade will be adopted to the engine. Cooling performance of the configuration stays equal to those of traditional methods, but this structure is much simpler than conventional ones. So the cost to make turbine blades will decrease. The representative company in this project, Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI) performed numerical simulation of flow field CFD in a turbine blade and measured cooling effectiveness of this configuration. In this study, cooling airflow in a turbine blade was visualized and flow velocity was measured with the particle image velocimetry (PIV). The purpose of the present study is to confirm usefulness of CFD and to find out some relationship between the flow field and heat transfer. Thus we made a comparison among experimental results and numerical simulation.