A scroll compressor comprising: a container; a frame fixedly coupled to the container and having a bearing hole formed therein; a fixed scroll fixedly coupled to the frame and having a fixed wrap formed therein; an orbiting scroll supported by the frame and including an orbiting wrap engaged with the fixed wrap to form continuously moving compression chambers, and further including a boss portion protruded toward the bearing hole to receive rotary power from a driving motor; and a crank shaft having a mainbearing portion which is supported by the bearing hole of the frame in the radial direction, to which the boss portion of the orbiting scroll is coupled, the crank shaft being configured to transfer rotary power from the driving motor to the orbiting scroll, wherein a boss coupling recess is formed in an end portion of the crank shaft such that the boss portion of the orbiting scroll is inserted into the boss coupling recess, and a bush bearing is provided on an outer circumferential surface of the boss portion and forms a bearing surface with an inner circumferential surface of the boss coupling recess, wherein the boss coupling recess is formed to be eccentric with respect to the central axis of the crank shaft, wherein, based on a diameter (d) of the boss portion of the orbiting scroll, a minimum gap (a) from an outer circumferential surface of the bush bearing to an inner circumferential surface of the boss coupling recess is within a range of d/20 < a < d/4, wherein the bush bearing has an annular cross-sectional shape, characterised in that the bush bearing is formed as a single member having self-lubricativeness, and wherein the bush bearing is press-fit onto the boss portion. a container; a frame fixedly coupled to the container and having a bearing hole formed therein; a fixed scroll fixedly coupled to the frame and having a fixed wrap formed therein; an orbiting scroll supported by the frame and including an orbiting wrap engaged with the fixed wrap to form continuously moving compression chambers, and further including a boss portion protruded toward the bearing hole to receive rotary power from a driving motor; and a crank shaft having a mainbearing portion which is supported by the bearing hole of the frame in the radial direction, to which the boss portion of the orbiting scroll is coupled, the crank shaft being configured to transfer rotary power from the driving motor to the orbiting scroll, a boss coupling recess is formed in an end portion of the crank shaft such that the boss portion of the orbiting scroll is inserted into the boss coupling recess, and a bush bearing is provided on an outer circumferential surface of the boss portion and forms a bearing surface with an inner circumferential surface of the boss coupling recess, wherein the boss coupling recess is formed to be eccentric with respect to the central axis of the crank shaft, based on a diameter (d) of the boss portion of the orbiting scroll, a minimum gap (a) from an outer circumferential surface of the bush bearing to an inner circumferential surface of the boss coupling recess is within a range of d/20 < a < d/4, wherein the bush bearing has an annular cross-sectional shape, characterised in that the bush bearing is formed as a single member having self-lubricativeness, and wherein the bush bearing is press-fit onto the boss portion.