This leak detection device is provided with a pulse signal output unit for respectively outputting predetermined pulse signals to the positive electrode connecting line connected to the positive electrode side of a battery and the negative electrode connecting line connected to the negative electrode side of the battery, a response waveform detection unit for detecting a positive electrode response waveform relative to the pulse signal outputted to the positive electrode connecting line and a negative electrode response waveform relative to the pulse signal outputted to the negative electrode connecting line, an amplitude ratio calculation unit for calculating the amplitude ratio on the basis of the positive electrode response waveform and the negative electrode response waveform, and a leak detection unit for detecting a leak between the battery and the ground on the basis of the amplitude ratio.
