A scroll compressor includes a pressing mechanism, a pushback mechanism and an adjustment mechanism. The pressing mechanism applies a pressing force toward a fixed scroll to the back side of an end plate portion of an orbiting scroll. The pushback mechanism applies a pushback force separating the orbiting scroll from a fixed scroll to the front of the orbiting scroll. The adjusting mechanism has a low-pressure portion filled with a fluid of a lower pressure than the discharge pressure of the compression mechanism, and a communicating groove formed in a sliding surface of an outer peripheral portion of the fixed scroll so as to communicate with the low-pressure portion in a first rotational angle range in order to reduce an upsetting moment of the orbiting scroll, and to be blocked from the low-pressure portion in a second rotational angle range other than the first rotational angle range.