To improve air leakage recovering efficiency.

There are provided an air leakage recovering apparatus 10 consisting of first and second air leakage recovering filters 22 and 24, first and third lifting pipelines 26 and 30, and a lifting means 34. The air leakage recovering filters 22 and 24 are placed immediately above a cutting edge 14 of a caisson main body 12. The first and third lifting pipelines 26 and 30 communicate with the filters 22 and 24, respectively. The pipelines 26 and 30 upward extend along a longitudinal axial direction of the main body, and open in an upper surface of the main body 12. Then, a lifting integrated pipe 36 opens in an opening, and the lifting means 34 communicates with the integrated pipe 36. When the lifting means 34 of the apparatus 10 is driven, ground water on the periphery of the filters 22 and 24 flows toward the filters, to thereby form an underground stream W on the periphery of the filters 22 and 24. When leaked air A rises up to an area where the underground stream W is created, even if rising speed of the leaked air A increases, the air can be absorbed and recovered in association with flow of the underground stream W.