Gas adsorption behavior on an epitaxial ferrite thin film was investigated. Ti doped ZnFe2O4
(ZFTO) thin film with 5nm thickness was epitaxially deposited on ZnFe2O4(ZFO, 10nm)/(001)YSZ substrate
by pulsed laser deposition (PLD). The resistance of the ZFTO film was increased by O2 adsorption, and the
resistance of the O2 adsorbed film was decreased on UV-light irradiation. The resistance decrease of the O2
adsorbed film on UV-light irradiation was due to O2 desorption and the increase of carrier density by electron
excitation.