New formation technique of metal oxide sensing film was proposed m this paper. Silicon wafer with Pt electrodes was used as a substrate for depositing metal Sn film. Metal Sn was deposited in the state of not continuous film but only island state. The samples were prepared to obtain the optimal condition of metal Sn deposition. The resistances of deposited Sn onto Pt electrodes amounted to $1;k{Omega}$, $5;k{Omega}$, $10;k{Omega}$ and $50;k{Omega}$, respectively. Also The sample with $1,500;{AA}$ thickness of Sn was prepared m order to compare sensing properties between conventional type and proposing type. After deposition of metal Sn, $SnO_2$ was formed by thermal oxidation method for 3 hrs. in $O_2$ ambient at $700^{circ}C$. Surface morphology, crystal structure and surface roughness of oxidized-sensing film were examined by SEM, XRD, and AFM, respectively. From the results of these analyses, the optimal deposition condition of Sn was that the Pt electrode resistance became $10;k{Omega}(300;{AA})$. Also, the sensing characteristics of fabricated sensing film for various concentrations of butane, propane and carbon monoxide gases were measured at he operating temperatures of $250^{circ}C$, $300^{circ}C$ and $350^{circ}C$, respectively. Although catalyst as not added to the sensing film, it has exhibited the high sensitivity to all the test gases.