Abstarct: Geothermal energy is one of the renewable energy resources which has been applied for electricity generation and local heating systems in different countries in recent years. Remote sensing is a new technology that can be used in geothermal field exploration for mapping minerals and thermal anomalies related to geothermal activities, delineating structural lineaments that are conduits of geothermal fluids and detection of hydrothermal alterations. Satellite data obtained from ASTER and ETM+ detector of Landsat 7 can be used for remote sensing studies. Because of goodness of Landsat 7 ETM+ data rather than ASTER data, in this research Mahallat Geothermal area in center of Iran in Markazi province is studied by Landsat 7 ETM+ data. The results of this study compared with the results of aeromagnetic and geochemical data analysis and the results obtained from remote sensing study are cross validated. According to the results of this research, it was found that Mahallat area is a part of an active and old geothermal system which it's reservoir is located in north of Mahallat city. There is a NW-SE fault in this area that transport water from reservoir to hot springs. According to the results of this research, a new area is suggested for complementary works in Mahallat geothermal area.