A scroll compressor includes a casing accommodating a rotary shaft and a driving unit, a first scroll making an orbiting movement by the rotary shaft, a second scroll engaged with the first scroll to form a compression chamber and having a bypass hole bypassing a refrigerant sucked into the compression chamber to an internal space of the casing, and a back-pressure chamber assembly pressing the second scroll toward the first scroll, wherein the back-pressure chamber assembly includes: a back-pressure space, a first valve unit allowing the bypass hole and the internal space of the casing to selectively communicate with each other, and a second valve unit opened and closed to selectively supply the refrigerant of the back-pressure space to the first valve unit to operate the first valve unit, and positioned to be fixed to the casing.