Abstract: A leakage detecting device for brake hoses is composed of a first cylinder chamber communicated with a brake hose to be inspected, a second cylinder chamber connected to a fluid pressure source, a leakage detecting cylinder with a piston disposed between the first and second cylinder chambers, displacement amount detecting means for detecting displacement of the piston of the leakage detecting cylinder and generating a signal corresponding to the displacement amount, and processing means for receiving the displacement detecting signal from the displacement amount detecting means, calculating leakage amount per unit time for a prescribed time based on the received signal, comparing data of the leakage amount per unit time with the upper limit value for leakage of a good product which is set by a setting device, and generating a failed product detected signal when the leakage amount exceeds the upper limit value for leakage of a good product.