Inulin is a group of natural polysaccharides that can be found in various plants. The inulin is widely used in many foods throughout the world due to its health-promoting and functional properties. The inulin 14-19 % was found in Jerusalem artichoke, which the plant found growing in Thailand. The aim of this study is to know yield of extraction by using ohmic heating method at three electrical field strengths (100, 150, 200 V/cm) at frequency 50 Hz.