METHOD OF QUANTIFYING SUBSTRATE

The invention provides a method of measuring a quantity of a substrate in a sample liquid by inserting a biosensor into a measuring device, the method comprising: providing the biosensor which includes: an insulating board; an electrode part which includes a counter electrode and a measuring electrode disposed on at least a part of the insulating board; a sample supplying path which supplies the sample liquid to the electrode part; and a reagent layer at least partially disposed in the sample supplying path; providing the measuring device which includes: a supporting section which detachably supports the biosensor; a connecting terminal which applies a voltage to the electrode part; and a driving power supply; applying the voltage to the electrode part by the driving power supply when the biosensor is inserted into the supporting section; detecting a start of supplying the sample liquid to the sample supplying path based on a first output signal from the electrode part; determining whether a sufficient quantity of the sample liquid is supplied to the sample supplying path based on a second output signal from the electrode part; measuring an elapsed time between the first output signal and the second output signal; measuring the quantity of the substrate of the sample liquid based on the second output signal from the electrode part; and if the elapsed time is within a predetermined time, correcting the measurement of the quantity of the substrate of the sample liquid based on the elapsed time.