The morphological effects of SnO2 thin film on catalytic activities and selectivities for the selective oxidation of CH4 were investigated with X-ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS). Dense texture type and a columnar texture type SnO2 thin films were prepared by the sputtering method. The measured proportion of adsorbed oxygen species (O2-, O-2(2-), O-2(-) and O-b) on these two types of samples with XPS were different from each other, and the proportion of a highly reactive oxygen species O- was larger on the dense sample. The TDS data of the products (HCHO, CH3OH, CO, CO2 and H2O) were obtained on the two different structured film samples after CH4 exposure at room temperature. The obtained TPD data were explained appropriately by considering several reaction pathways. The dense texture type SnO2 film showed a higher reactivity for the oxidation of CH4 than that of the columnar texture type one. The selective formation of HCHO was especially observed for the dense texture film. The oxidation of CH4 was therefore strongly affected by the surface morphology of SnO2 film.