A scroll compressor comprising: a fixed scroll; a movable scroll that can revolve with respect to the fixed scroll; and a crankshaft that can rotate causing the movable scroll to revolve, wherein a discharge port is formed in one of the fixed scroll or the movable scroll and a cutout portion is formed in an outer edge of the other the cutout portion formed in the other at least partially passes through the profile of the discharge port formed in the one because of the revolution of the movable scroll, the fixed scroll and the movable scroll define compression chambers for compressing a fluid, the other at least partially covers the discharge port and thereby can change a communication area that is the area of a portion of the total area of the discharge port that contributes to communication with the compression chambers, wherein as the crankshaft rotates from a first rotation angle position (θ1), that corresponds to a disposition in which the compression chambers and the discharge port start communicating with each other, to a second rotation angle position (θ2), that is a preliminary discharge interval angle (Δθ) greater than the first rotation angle position (θ1), the communication area increases at a first rate of increase, and wherein as the crankshaft rotates from the second rotation angle position to a third rotation angle position (θ3), that is greater than the second rotation angle position, the communication area increases at a second rate of increase, and the second rate of increase is greater than the first rate of increase, characterized in that the third rotation angle position (θ3) is 90° or more greater than the second rotation angle position (θ2). a fixed scroll; a movable scroll that can revolve with respect to the fixed scroll; and a crankshaft that can rotate causing the movable scroll to revolve, wherein a discharge port is formed in one of the fixed scroll or the movable scroll and a cutout portion is formed in an outer edge of the other the cutout portion formed in the other at least partially passes through the profile of the discharge port formed in the one because of the revolution of the movable scroll, the fixed scroll and the movable scroll define compression chambers for compressing a fluid, the other at least partially covers the discharge port and thereby can change a communication area that is the area of a portion of the total area of the discharge port that contributes to communication with the compression chambers, wherein as the crankshaft rotates from a first rotation angle position (θ1), that corresponds to a disposition in which the compression chambers and the discharge port start communicating with each other, to a second rotation angle position (θ2), that is a preliminary discharge interval angle (Δθ) greater than the first rotation angle position (θ1), the communication area increases at a first rate of increase, and wherein as the crankshaft rotates from the second rotation angle position to a third rotation angle position (θ3), that is greater than the second rotation angle position, the communication area increases at a second rate of increase, and the second rate of increase is greater than the first rate of increase, characterized in that the third rotation angle position (θ3) is 90° or more greater than the second rotation angle position (θ2).