A scroll compressor is provided which includes: a revolving scroll, a fixed scroll, an autorotation preventing mechanism, a frame, a crank shaft provided with an eccentric pin portion which is eccentric with respect to an axis, the crank shaft being provided with a flange portion at a lower portion of the eccentric pin portion, the flange portion being larger than the diameter of the eccentric pin portion, a balance weight mounted on the flange portion, a sealing member performing sealing between the revolving scroll and the flange portion, and a thrust bearing arranged between the frame and the flange portion. The scroll compressor reduces the amount of oil flowing into a back pressure chamber, thereby improving the performance of the scroll compressor.