An impeller for a centrifugal rotary machine comprising: a disk that has a disk shape and is configured to rotate around an axis; a plurality of blades that are provided at intervals in a circumferential direction on a side of a surface of the disk toward a direction of the axis and extend to a rear side in a rotation direction as the plurality of the blades go toward an outer side in a radial direction; and a cover that covers the plurality of blades in the direction of the axis, wherein each of the plurality of the blades has: a primary blade which extends to the rear side in the rotation direction as the primary blade goes from an inner side toward the outer side in the radial direction and of which a rear edge is positioned on the inner side with respect to an outer circumferential edge portion of the disk in the radial direction, and a secondary blade (90a, 90b) which is provided at intervals on a side in front of the primary blade in the rotation direction to correspond to the primary blade, of which a front edge is positioned on the outer side with respect to a front edge of the primary blade in the radial direction, and of which a rear edge is positioned on the outer circumferential edge portion of the disk, said impeller being characterized in that when a region between the disk and the cover facing each other in the direction of the axis is divided into a disk side region, a cover side region, and a central region between the disk side region and the cover side region, the secondary blade (90a, 90b) is not provided in the central region but is provided in the disk side region and the cover side region. a disk that has a disk shape and is configured to rotate around an axis; a plurality of blades that are provided at intervals in a circumferential direction on a side of a surface of the disk toward a direction of the axis and extend to a rear side in a rotation direction as the plurality of the blades go toward an outer side in a radial direction; and a cover that covers the plurality of blades in the direction of the axis, wherein each of the plurality of the blades has: a primary blade which extends to the rear side in the rotation direction as the primary blade goes from an inner side toward the outer side in the radial direction and of which a rear edge is positioned on the inner side with respect to an outer circumferential edge portion of the disk in the radial direction, and a secondary blade (90a, 90b) which is provided at intervals on a side in front of the primary blade in the rotation direction to correspond to the primary blade, of which a front edge is positioned on the outer side with respect to a front edge of the primary blade in the radial direction, and of which a rear edge is positioned on the outer circumferential edge portion of the disk, said impeller being characterized in that when a region between the disk and the cover facing each other in the direction of the axis is divided into a disk side region, a cover side region, and a central region between the disk side region and the cover side region, the secondary blade (90a, 90b) is not provided in the central region but is provided in the disk side region and the cover side region. a primary blade which extends to the rear side in the rotation direction as the primary blade goes from an inner side toward the outer side in the radial direction and of which a rear edge is positioned on the inner side with respect to an outer circumferential edge portion of the disk in the radial direction, and a secondary blade (90a, 90b) which is provided at intervals on a side in front of the primary blade in the rotation direction to correspond to the primary blade, of which a front edge is positioned on the outer side with respect to a front edge of the primary blade in the radial direction, and of which a rear edge is positioned on the outer circumferential edge portion of the disk, said impeller being characterized in that when a region between the disk and the cover facing each other in the direction of the axis is divided into a disk side region, a cover side region, and a central region between the disk side region and the cover side region, the secondary blade (90a, 90b) is not provided in the central region but is provided in the disk side region and the cover side region.