Thin films of InSb with different thickness (t = 5, 10 and 15 kÅ) were deposited on to glass substrate by flash evaporation technique. The structural and electrical properties were investigated and the effect of films thickness on films properties was discussed. XRD analysis of the films as a function of film thickness revealed that crystallinity improves with film thickness. Temperature dependence of the Hall parameters were studied in a wide range, 20 < T < 300 K. The temperature variation of the Hall coefficient and conductivity shows an activated nature with negative temperature coefficient confirming that the prepared films of InSb are semiconducting in nature with n-type conductivity. Size effect was observed as the defect density is much smaller for thicker films and as a result electrical conductivity of the films increases with increasing film thickness with the increase of the charge carriers through the film. An increase in mobility with sample thickness has been observed. The mobility variations with temperature revealed a transition from lattice to impurity scattering in the observed temperature range.