The invention relates to a method for leakage detection on at least one flexible test piece in a film chamber, including inserting the at least one test piece into a film chamber, lowering the pressure in the film chamber outside the at least one test piece, and detecting a leakage in the at least one test piece by observing the spatial change of the film of the film chamber. The outer contour of the at least one test piece is transferred to at least one section of the film by the lowering of the pressure in the film chamber. The contour of the film is recorded with an image recording system, and the recorded images of the contour are compared with reference images of said contour in the event of a tight test piece.