InSb evaporated films for magnetic sensors are prepared by controlling the evaporation rate and the substrate temperature gradient in order to obtain elements of high sensitivity. There are In needles in the films which are precipitated parallel to one another during the evaporation process. The In needles have diameters of 0.5∼2 &mgr;m and lengths of 50∼200 &mgr;m. The films have thicknesses of 1.0∼3.5 &mgr;m. The results of the sensing characteristics and crystalline structure of InSb films are presented. The latter was analyzed by an electron microscope. A magnetoresistance value (&Dgr;R/R0) of 1400% is obtained at a length‐to‐width ratio (l/W) of 0.1 and an applied magnetic flux density (B) of 1 Wb/m2(=T), at room temperature.