A scroll compressor, comprising: a partition plate for partitioning an interior of a hermetic container into a high pressure space and a low pressure space; a fixed scroll which is adjacent to the partition plate; an orbiting scroll which is meshed with the fixed scroll and which forms a compression chamber; a rotation-restraining member for preventing the orbiting scroll from rotating; and a main bearing for supporting the orbiting scroll, in which the fixed scroll, the orbiting scroll, the rotation-restraining member and the main bearing are placed in the low pressure space, and the fixed scroll and the orbiting scroll are placed between the partition plate and the main bearing, wherein the scroll compressor further includes a bearing-side concave portion formed in an upper surface of the main bearing, a scroll-side concave portion formed in a lower surface of the fixed scroll, and a columnar member having a lower end inserted into the bearing-side concave portion and an upper end inserted into the scroll-side concave portion, wherein the columnar member can slide with at least one of the bearing-side concave portion and the scroll-side concave portion, thereby permitting the fixed scroll to move in an axial direction of the fixed scroll between the partition plate and the main bearing, characterized in that either a fitting gap between the bearing-side concave portion and the columnar member and a fitting gap between the scroll-side concave portion and the columnar member are different from each other; or that an insertion portion of the columnar member of the bearing-side concave portion is provided with a pin hole, and the pin hole is provided with a retaining pin of the columnar member. a partition plate for partitioning an interior of a hermetic container into a high pressure space and a low pressure space; a fixed scroll which is adjacent to the partition plate; an orbiting scroll which is meshed with the fixed scroll and which forms a compression chamber; a rotation-restraining member for preventing the orbiting scroll from rotating; and a main bearing for supporting the orbiting scroll, in which the fixed scroll, the orbiting scroll, the rotation-restraining member and the main bearing are placed in the low pressure space, and the fixed scroll and the orbiting scroll are placed between the partition plate and the main bearing, wherein the scroll compressor further includes a bearing-side concave portion formed in an upper surface of the main bearing, a scroll-side concave portion formed in a lower surface of the fixed scroll, and a columnar member having a lower end inserted into the bearing-side concave portion and an upper end inserted into the scroll-side concave portion, wherein the columnar member can slide with at least one of the bearing-side concave portion and the scroll-side concave portion, thereby permitting the fixed scroll to move in an axial direction of the fixed scroll between the partition plate and the main bearing, characterized in that either a fitting gap between the bearing-side concave portion and the columnar member and a fitting gap between the scroll-side concave portion and the columnar member are different from each other; or that an insertion portion of the columnar member of the bearing-side concave portion is provided with a pin hole, and the pin hole is provided with a retaining pin of the columnar member.