To provide a water-leakage position detection device and method therefor capable of improving accuracy for detecting a water-leakage position by preventing detection faults due to the influence of a short-circuit path passing through inside of and/or around a sealing work construction or a short-circuit path passing through a water-leakage part apart from a position of an applied electrode.

This water-leakage position detection device is provided with the sealing work construction 1, wherein an isolation sealing work 2 is provided in a depression formed on the ground, a planar electrode 12 installed on a front surface or a reverse surface of the sealing work 2, plural point electrodes installed on a side opposite to the planar electrode 12, a selection connecting means 15 for selecting one of the point electrodes from among the plural point electrodes and connecting the selected point electrode to an end of a power supply 4 and connecting all the point electrodes, except the selected point electrode and the planar electrode 12 to the other end of the power supply 4, and a current-measuring means 5 for measuring a current flowing between the selected point electrode and the planar electrode 12. The water-leakage position of the sealing work construction 1 can be detected by the measured current value and the position of the selected point electrode.