Very thin InSb films for elastic surface wave amplifiers were prepared by a source-temperature-programed evaporation method and their crystalline and electrical properties were studied. Optimum source and substrate temperatures to obtain stable thin films with good properties were investigated. A considerable improvement in the mobility of InSb films is observed by overlaying SiO film on the deposited InSb films. Moreover, their InSb thin films of width of about 97 µm and length of 7mm were fabricated on 131° roteted Y-cut X-propagation LiNbO3 by using a photoetching technics. We obtained the thin films with drift mobility of 1000cm2V-1s-1 and ovserved an electronic gain of 11.5 dB/7 mm at the continuous operation.