PURPOSE: To obtain a film-type gas sensor having the low resistance and the high gas selectivity.
CONSTITUTION: A pair of electrodes 4 and 6 and a metal-oxide semiconductor film 2 are formed on a substrate 16. A surface electrode 8 is laminated on the metal oxide semiconductor film 2. The parts facing a pair of electrodes 4 and 6 on the substrate 16 are provided on the surface electrode 8. A current is bypassed with the surface electrode 8 and made to flow through the metal oxide semiconductor film 2 vertically with respect to the substrate 16. As a result, the low-resistance gas sensor is obtained. Gas such as ethanol is oxidized and removed by the catalyst activity between the electrodes 4 and 6 on the substrate 16 and the surface electrode 8. Thus, the gas selectivity is obtained. When the surface electrode is made minute, the removing effect of the ethanol and the like with the electrode is displayed especially intensively.
YAMAGUCHI TAKASHI
MURAYAMA HIDEMI
