[Objective] An object is to provide a sensor control apparatus and a sensor-control-apparatus control method which can reduce variation in startup time among a plurality of times of execution of detection processing, in consideration of variation in output characteristic among a plurality of gas sensors.[Means for Solution] In a sensor control apparatus, before drive control (S55 to S80) is started, preliminary control is executed so as to supply a constant current to a second oxygen pump cell over a constant time, to thereby control to a constant level the amount of oxygen pumped from a second measurement chamber to the outside of the second measurement chamber (S40 to 50). The preliminary control is executed under control conditions of the sensor control apparatus which are determined for each gas sensor and are associated with the amount of oxygen pumped from the second measurement chamber to the outside thereof. The control conditions bring into a target range the concentration correspondence value calculated after start of the drive control which is started after the preliminary control is executed in a state in which a reference gas having a known concentration is introduced into the gas sensor.