It is proposed that important magnetic properties of the surface materials on Mars be measured by a simple instrument comprising a flux gate magnetometer and a magnetizing coil. The paper describes the basic construction principles and demonstrates the instrument's usability on a few materials that are expected to be similar to those on Mars. Very small traces of ferromagnetic materials can be detected by the measuring technique. In addition to materials studies, the instrument is suitable for magnetospheric, paleomagnetic, and magnetotelluric sounding measurements. ¿ American Geophysical Union 1992