DETECTOR FOR DETECTING DETECTION TARGET SUBSTANCE

PROBLEM TO BE SOLVED: To provide a detector for detecting a detection target substance, that is capable of performing rapid detection and measurement.SOLUTION: A detector 1 for detecting a detection target substance includes: a sensor 10 having an electrode 12 for electrochemically detecting the detection target substance; voltage applying means 20 for applying a voltage to the electrode 12; and current measuring means 30 for measuring a value of electric current flowing in the electrode 12 when the voltage is applied with the voltage applying means 20. The voltage applying means 20 is configured to apply a voltage of an initial voltage value V0 which is larger than a setting voltage value V1, before applying a voltage of the setting voltage value V1 being a target, and thereafter to apply the voltage of the setting voltage value V1 by reducing the voltage value of the voltage to be applied from the initial voltage value V0 to the setting voltage value V1.