SCROLL COMPRESSOR

PROBLEM TO BE SOLVED: To provide a scroll compressor including an injection flow passage, the scroll compressor having reliability which can be prevented from degrading due to over-compression, by enabling over-compressed refrigerant during a total process immediately after completion of suction of the refrigerant to discharge of the refrigerator to be instantly relieved.SOLUTION: An injection port 1f is communicated with an injection flow passage 31a for supplying a refrigerant to a compression chamber 20 during compression. An over-compression preventive relief port 1h is provided in a fixed scroll 1 and relieves the refrigerant over-compressed in the compression chamber 20 to outside the compression chamber 20. The injection port 1f and the over-compression preventive relief port 1h are provided in such a way that any one of the injection port 1f and the over-compression preventive relief port 1h is communicated with the compression chamber 20 during the entire process from completion of suction to discharge in the compression chamber 20, and an abnormal pressure increase preventive relief port for relieving the refrigerant over-compressed in the compression chamber 20 to outside the compression chamber 20 is provided in the injection flow passage 31a.