To attempt enhancing reliability of bubble inspection using ultrasonic wave and realizing cost-lowering.

The ultrasonic leakage position detection device is equipped with: an ultrasonic transmitter/receiver section 20 capable of irradiating ultrasonic wave to suspension L and receiving the reflected wave R; a transmitted wave receiver 30 prepared at a position receivable to transmitted wave T of ultrasonic wave; and a bubble detector detecting existence or nonexistence of and conditions of bubbles based on the signals of reflected wave R received by the reflected wave receiver section 20 and signals of the transmitted wave T received by transmitted wave receiver 30. At a condition that a test object W is sunk to be arranged at a lower position than the level surface at which the ultrasonic transmitter/receiver section 20 and the transmitted wave receiver 30 are prepared in a suspension tank 10 storing suspension L, so as to pass babbles leaked from the test object W through a gap between the ultrasonic transmitter/receiver section 20 and the transmitted wave receiver 30. Ultrasonic wave is radiated from the ultrasonic transmitter to inspect existence or nonexistence of air leakage, conditions of bubbles, and volume of air leakage at the bubble detector based on the signals of reflected wave R and transmitted wave T.