In general, an analysis of the claw-pole type alternator was performed through 3 dimensional finite element analysis (3D FEA) or magnetic equivalent circuit (MEC). However, 3D FEA needs much computation time and many computer memories. Also MEC has the difficulty to define the main flux path on electric machine including the complex shape. In this paper, to overcome this shortcoming, we propose an analysis method applying 2D Fourier series and 3D FEA for obtaining and accurate analysis result with also saving computation time. To confirm analysis method, analysis waveforms and measurement waveforms for induced electromotive force (EMF) of each phase were compared.