Duennschicht-Gassensor

The invention relates to a thin-film gas sensor on a flat, inert, heatable substrate (2) provided with a passivation layer (7) and a deposited gas-sensitive SnO<-2 layer (6) connected to contact electrodes (3,4), whereby the gas-sensitive SnO<-2 layer (6) can be doped with catalyst material or at least can be partially provided with a layer (5) containing a catalyst material, whereby the sensitive layer (6) is CO<-2-sensitive, whereby the sensitive layer (6) and/or the surface, if necessary, the catalyst layer (5), contains Ca and/or Ca-oxide promotors