A centrifugal compressor, comprising: a compressor wheel fixed to an end portion of a rotating shaft; a compressor housing configured to accommodate the compressor wheel; an air intake space formed in the compressor housing, provided extending on an extension line of the rotating shaft, and located on a front side of the compressor wheel; a downstream-side flow passage provided on an outside in a radial direction of the rotating shaft with respect to the compressor wheel, configured to guide fluid sucked from the air intake space and compressed by the compressor wheel, to the outside of the compressor housing; a return flow passage provided with one end and another end, the one end opened to a wall surface of the compressor housing that forms the downstream-side flow passage, and the other end opened to a wall surface of the compressor housing that forms the air intake space, the return flow passage configured to circulate the fluid guided by the downstream-side flow passage, from the downstream-side flow passage to the air intake space; characterized by further comprising an introduction portion provided in the air intake space, including an outer peripheral surface brought into contact with the wall surface forming the intake space on an upstream side of the outer peripheral surface in a flowing direction of the fluid, and an inner peripheral surface forming a flow passage to guide fluid from the outside of the compressor housing into the air intake space, and a ring-shaped passage provided between the outer peripheral surface of the introduction portion and the wall surface of the compressor housing forming the air intake space, the ring-shaped passage circularly extending in a rotational direction of the rotating shaft; wherein the inner peripheral surface includes a downstream end in the flowing direction of the fluid, the downstream end is located more inward in the radial direction of the rotating shaft than the wall surface forming the intake space, and at least part of the other end of the return flow passage overlaps with the introduction portion when viewed from a radial direction of the rotating shaft. a compressor wheel fixed to an end portion of a rotating shaft; a compressor housing configured to accommodate the compressor wheel; an air intake space formed in the compressor housing, provided extending on an extension line of the rotating shaft, and located on a front side of the compressor wheel; a downstream-side flow passage provided on an outside in a radial direction of the rotating shaft with respect to the compressor wheel, configured to guide fluid sucked from the air intake space and compressed by the compressor wheel, to the outside of the compressor housing; a return flow passage provided with one end and another end, the one end opened to a wall surface of the compressor housing that forms the downstream-side flow passage, and the other end opened to a wall surface of the compressor housing that forms the air intake space, the return flow passage configured to circulate the fluid guided by the downstream-side flow passage, from the downstream-side flow passage to the air intake space; characterized by further comprising an introduction portion provided in the air intake space, including an outer peripheral surface brought into contact with the wall surface forming the intake space on an upstream side of the outer peripheral surface in a flowing direction of the fluid, and an inner peripheral surface forming a flow passage to guide fluid from the outside of the compressor housing into the air intake space, and an outer peripheral surface brought into contact with the wall surface forming the intake space on an upstream side of the outer peripheral surface in a flowing direction of the fluid, and an inner peripheral surface forming a flow passage to guide fluid from the outside of the compressor housing into the air intake space, and a ring-shaped passage provided between the outer peripheral surface of the introduction portion and the wall surface of the compressor housing forming the air intake space, the ring-shaped passage circularly extending in a rotational direction of the rotating shaft; wherein the inner peripheral surface includes a downstream end in the flowing direction of the fluid, the downstream end is located more inward in the radial direction of the rotating shaft than the wall surface forming the intake space, and at least part of the other end of the return flow passage overlaps with the introduction portion when viewed from a radial direction of the rotating shaft.