PURPOSE: To eliminate leakage of compressed fluid and enhance the compressing performance by providing an oil sump groove stretching along a spiral element at the slide surface of a chip seal to be furnished on the spiral element which is mating with an end plate, and thereby certainly sealing the gap between the element and the end plate with this chip seal.

CONSTITUTION: An oil sump groove 10 stretching along a spiral element 3 is formed at the slide surface 91 of a chip seal 9. This provides labyrinth seal effect, and the surface pressure of the end plate 2 given by the slide surface 91 is increased. Accordingly the gap between the spiral element 3 and end plate 2 is sealed certainly with the chip seal 9 to eliminate leakage of the compressed fluid, which shoud enhance the compressing performance.