A sample supply detection method for detecting, in sample analysis using an analytical tool including a flow path for moving a sample, whether or not a necessary amount of sample is supplied to the flow path, the analytical tool further including a working electrode and a counter electrode for applying a voltage to the sample supplied to the flow path and measuring a detection current detected during the voltage application, the method comprising: a step of forming a potential difference between the working electrode and the counter electrode; a step of measuring a detection current between the working electrode and the counter electrode; a first determination step of determining whether or not the detection current has exceeded a predetermined threshold; a second determination step of determining whether or not a peak appears in a time course of the detection current between the working electrode and the counter electrode before lapse of a predetermined period from when the detection current exceeded the threshold, the second determination step being performed in the case where it is determined in the first determination step that the detection current between the working electrode and the counter electrode has exceeded the threshold;and a third determination step of determining whether or not the detection current between the working electrode and the counter electrode monotonically decreases after the peak detection in the case where the peak is detected in the second determination step; characterized by a fourth determination step of determining whether or not a necessary amount of sample is properly supplied to the flow path based on the determination in the first through the third determination steps only; wherein the necessary amount of sample is properly supplied to the flow path when the detection current has exceeded the predetermined threshold, a peak is detected before the lapse of the predetermined period, and when the detection current monotonically decreases after the peak detection. a step of forming a potential difference between the working electrode and the counter electrode; a step of measuring a detection current between the working electrode and the counter electrode; a first determination step of determining whether or not the detection current has exceeded a predetermined threshold; a second determination step of determining whether or not a peak appears in a time course of the detection current between the working electrode and the counter electrode before lapse of a predetermined period from when the detection current exceeded the threshold, the second determination step being performed in the case where it is determined in the first determination step that the detection current between the working electrode and the counter electrode has exceeded the threshold;and a third determination step of determining whether or not the detection current between the working electrode and the counter electrode monotonically decreases after the peak detection in the case where the peak is detected in the second determination step; characterized by a fourth determination step of determining whether or not a necessary amount of sample is properly supplied to the flow path based on the determination in the first through the third determination steps only; wherein the necessary amount of sample is properly supplied to the flow path when the detection current has exceeded the predetermined threshold, a peak is detected before the lapse of the predetermined period, and when the detection current monotonically decreases after the peak detection.