The　structural　and　gas-sensitive　properties　of　n-N　SnO2/?(e)-Ga2O3:Sn　heterostructures　were　investigated　in　detail　for　the　first　time.　The　?(e)-Ga2O3:Sn　and　SnO2　films　were　grown　by　the　halide　vapor　phase　epitaxy　and　the　high-frequency　magnetron　sputtering,　respectively.　The　gas　sensor　response　and　speed　of　operation　of　the　structures　under　H-2　exposure　exceeded　the　corresponding　values　of　single　?(e)-Ga2O3:Sn　and　SnO2　films　within　the　temperature　range　of　25-175　&　DEG;C.　Meanwhile,　the　investigated　heterostructures　demonstrated　a　low　response　to　CO,　NH3,　and　CH4　gases　and　a　high　response　to　NO2,　even　at　low　concentrations　of　100　ppm.　The　current　responses　of　the　SnO2/?(e)-Ga2O3:Sn　structure　to　10(4)　ppm　of　H-2　and　100　ppm　of　NO2　were　30-47　arb.　un.　and　3.7　arb.　un.,　correspondingly,　at　a　temperature　of　125　&　DEG;C.　The　increase　in　the　sensitivity　of　heterostructures　at　low　temperatures　is　explained　by　a　rise　of　the　electron　concentration　and　a　change　of　a　microrelief　of　the　SnO2　film　surface　when　depositing　on　?(e)-Ga2O3:Sn.　The　SnO2/?(e)-Ga2O3:Sn　heterostructures,　having　high　gas　sensitivity　over　a　wide　operating　temperature　range,　can　find　application　in　various　fields.