To raise work efficiency by facilitating the survey work of leak locations.

A portable leak detector R is provided with a microphone 3 for detecting ultrasonic generated at fluid leak locations, an input means 17 for inputting the information of the leak locations surveyed based on the output signal of the microphone 3 by moving in a survey area, an imaging mean 21 photographing the leak locations, a display means 19 for indicating the location information input by the input means 17 and the images Pb of the leak locations photographed with the imaging means 21, and a data processing means 17 for making stored state correlating the output data of the microphone 3, in put location information from the inputting means 17 and the photographed images Pb by the photographing means 21 about the same leak location.