A 3-D resistivity structure determined from a small number of MT stations sparsely distributed around the Mae Chan geothermal area provides very useful information to assess the potential for a geothermal power plant. In the Mae Chan hydrothermal system, hot fluid heated from the deeper granitic batholith, identified as high resistivity feature R, is stored in the fractured and weathered gran- ite and the sedimentary rock indicated by two conductive zones C1 and C2. A fracture in the damaged zone of the fault (shown as a resistivity contrast) allows the pressurized hot fluid to reach the surface. Since the temperature of the Mae Chan hydrothermal system does not seem to be high, we propose the development of small-scale geothermal power plants over the two zones C1 and C2. Further detailed investigation with more MT coverage along with deep well drilling may be necessary in order to assess the potential to build a larger scale geothermal power plant in the area.