It is important to analyse the characteristic of the flux density and eddy current on the inner part of the electric machine in order to raise the efficiency of the machine. In general, characteristics of the machines are investigated using the numerical analysis. In this study, we present a novel measuring method of the flux density and eddy current on the surface of the sheet iron using the search coil and needle. As the application model of the measuring method, we have used an eddy current brake which is a new assistance brake system of large sized vehicles.