The gas sensor control device

PROBLEM TO BE SOLVED: To provide a gas sensor control device capable of suppressing an influence due to COgas in a to-be-measured gas in acquiring information about HO gas in the to-be-measured gas by using a gas sensor.SOLUTION: A gas sensor control device 1 of a gas sensor 2 equipped with an electromotive force cell 24 and a pump cell 14 includes: current control means 69 for controlling a pump current Ip such that an electromotive force cell voltage Vs becomes a target voltage Vr; first current detection means S8 for detecting a first pump current Ip1 in the state that the electromotive force cell voltage Vs becomes a first target voltage Vr1 where HO gas in a to-be-measured gas EG dissociates; equivalent current acquisition means S7, S10 for acquiring the value of a COequivalent current Icoe equivalent to a current flowing due to dissociation of COgas in the to-be-measured gas EG resulting from being the first target voltage Vr1; and cancellation means S11 for acquiring a cancellation pump current in which an influence of dissociation of COgas included in the first pump current Ip1 is cancelled by using the COequivalent current Icoe.