A scroll compressor comprising a capacity varying apparatus, the capacity varying apparatus comprising: at least one low pressure passage configured to communicate with a low pressure area of the scroll compressor; at least one intermediate pressure passage configured to communicate with an intermediate pressure area of a plurality of compression pockets of the scroll compressor; and a capacity varying device comprising a plurality of discs (310, 320, 330; 350, 360) configured to selectively allow communication between the at least one low pressure passage and the at least one intermediate pressure passage based on a desired capacity, characterized in that the plurality of discs comprise: a fixed disc (310; 350) being fixed in an installation groove formed in a compression opposite surface of a fixed scroll of the scroll compressor, and having at least one low pressure communication hole (312, 313; 352, 353) and at least one intermediate pressure communication hole (314, 315; 354, 355); and at least one rotatable disc (320, 330; 360) being rotatable mounted to the fixed disc (310; 350), having a plurality of connection grooves (332, 333; 362, 363) configured to allow communication between the at least one low pressure passage and the at least one intermediate pressure passage based on a position of the at least one rotatable disc, and wherein a depth of the installation groove formed in the compression opposite surface of the fixed scroll is the same as a sum of the thickness of the fixed disc and the rotatable disc. at least one low pressure passage configured to communicate with a low pressure area of the scroll compressor; at least one intermediate pressure passage configured to communicate with an intermediate pressure area of a plurality of compression pockets of the scroll compressor; and a capacity varying device comprising a plurality of discs (310, 320, 330; 350, 360) configured to selectively allow communication between the at least one low pressure passage and the at least one intermediate pressure passage based on a desired capacity, characterized in that the plurality of discs comprise: a fixed disc (310; 350) being fixed in an installation groove formed in a compression opposite surface of a fixed scroll of the scroll compressor, and having at least one low pressure communication hole (312, 313; 352, 353) and at least one intermediate pressure communication hole (314, 315; 354, 355); and at least one rotatable disc (320, 330; 360) being rotatable mounted to the fixed disc (310; 350), having a plurality of connection grooves (332, 333; 362, 363) configured to allow communication between the at least one low pressure passage and the at least one intermediate pressure passage based on a position of the at least one rotatable disc, and wherein a depth of the installation groove formed in the compression opposite surface of the fixed scroll is the same as a sum of the thickness of the fixed disc and the rotatable disc. a fixed disc (310; 350) being fixed in an installation groove formed in a compression opposite surface of a fixed scroll of the scroll compressor, and having at least one low pressure communication hole (312, 313; 352, 353) and at least one intermediate pressure communication hole (314, 315; 354, 355); and being fixed in an installation groove formed in a compression opposite surface of a fixed scroll of the scroll compressor, and having at least one low pressure communication hole (312, 313; 352, 353) and at least one intermediate pressure communication hole (314, 315; 354, 355); and at least one rotatable disc (320, 330; 360) being rotatable mounted to the fixed disc (310; 350), having a plurality of connection grooves (332, 333; 362, 363) configured to allow communication between the at least one low pressure passage and the at least one intermediate pressure passage based on a position of the at least one rotatable disc, and wherein a depth of the installation groove formed in the compression opposite surface of the fixed scroll is the same as a sum of the thickness of the fixed disc and the rotatable disc. being rotatable mounted to the fixed disc (310; 350), having a plurality of connection grooves (332, 333; 362, 363) configured to allow communication between the at least one low pressure passage and the at least one intermediate pressure passage based on a position of the at least one rotatable disc, and wherein a depth of the installation groove formed in the compression opposite surface of the fixed scroll is the same as a sum of the thickness of the fixed disc and the rotatable disc.