Undoped and Zn-doped SnO sub(2) thin films are deposited onto glass substrates by sol-gel spin coating method. All the films are characterized by X-ray photon spectroscopy (XPS) and Fourier transform infra-red spectroscopy (FTIR). XPS shows that Sn presence as valence of Sn super(4+) in the prepared SnO sub(2) thin films instead of Sn super(2+). In addition, it also exhibits the amount of Zn in SnO sub(2) thin films, which increases with increasing Zn doping percentage. The Zn (2P sub(3/2)) peak is symmetric and centred at around 1,021.73 eV which shifts to the lower binding energy of 1,020.83 eV for 15 at.% Zn doped SnO sub(2) thin film. FTIR study is used to describe the local environment of undoped and Zn-doped SnO sub(2) thin films which also confirms the synthesis of undoped and Zn-doped SnO sub(2) thin films. It is found that the resistance of SnO sub(2) thin films increases as Zn doping concentration increases at room humidity. The resistance of all the samples increases as relative humidity (RH) increases. The sensitivity of SnO sub(2) thin films increases as RH increases while it decreases as Zn doping percentage increases. Response time of SnO sub(2) thin film decreases as Zn doping percentage increases and recovery time slightly increases with doping percentage.