Centrifugal rotary machine

A centrifugal rotary machine comprising:

• an impeller including a disk formed to have a disc-shape which rotates around an axis, blades which define and form a flow path extending from one axial side toward a radially outer side between each other by being provided at intervals in a circumferential direction on a surface facing one axial side of the disk, and a cover which covers the blades from a radially outer side;
• a casing which accommodates the impeller radially inward and forms a gap between the casing and an outer circumferential surface of the cover;
• and
• a sealing device which seals the gap,
• wherein the casing includes
• an end wall surface which is disposed to face one axial side of a cover end surface facing one axial side of the cover, extends in a radial direction and forms a radial flow path between the end wall surface and the cover end surface, and
• a foreign matter introduction path which is formed inside the casing and communicates with a radially outer side of the radial flow path.