After the tooth portion 102b of the stationary scroll 102 and the tooth portion 103b of the revolving scroll 103 have contacted each other on one contact face 121 in the central portion of the scroll (shown in FIG. 5A), when this contact face 121 is shifted to two sliding contact portions 122, 123, the operating chamber V is formed between the two sliding contact portions 122, 123 (shown in FIG. 5B), and the refrigerant introducing port 105a is open to the region on the contact face 121. Accordi...