An impeller for a centrifugal turbomachine, comprising: a hub having a small-diameter portion positioned at a first end portion in an axial direction and a large-diameter portion positioned at a second end portion in the axial direction, the large-diameter portion having a greater diameter than the small-diameter portion; and a blade having a first edge positioned at an axial-directional position of the small-diameter portion and a second edge positioned at an axial-directional position of the large-diameter portion, the blade being disposed on an outer peripheral surface of the hub, wherein the impeller is configured such that, when a first radial-directional cross section (S 1) is a cross section of the impeller at an axial-directional position passing a tip of the first edge, at least a part of the first radial-directional cross section (S 1) in a blade-height range of 50% or more is inclined downstream in a rotational direction of the impeller with respect to a radial direction, wherein the impeller is configured such that, when a second radial-directional cross section (S 2) is a cross section of the impeller at an axial-directional position passing a tip of the second edge, at least a part of the second radial-directional cross section (S 2) in a blade-height range of 50% or more is inclined upstream in the rotational direction of the impeller with respect to the radial direction, wherein, when, on a second reference line (L 2) connecting midpoints of the second radial-directional cross section (S 2) in a blade thickness direction, a second hub-side reference point (Ph 2) is defined as a radial-directional position of a hub surface of the hub and a second tip-side reference point (Pt 2) is defined as a radial-directional position of the tip, the second-tip side reference point (Pt 2) is positioned upstream of the second hub-side reference point (Ph 2) in the rotational direction, characterized in that the second reference line (L 2) includes a linear portion. a hub having a small-diameter portion positioned at a first end portion in an axial direction and a large-diameter portion positioned at a second end portion in the axial direction, the large-diameter portion having a greater diameter than the small-diameter portion; and a blade having a first edge positioned at an axial-directional position of the small-diameter portion and a second edge positioned at an axial-directional position of the large-diameter portion, the blade being disposed on an outer peripheral surface of the hub, wherein the impeller is configured such that, when a first radial-directional cross section (S 1) is a cross section of the impeller at an axial-directional position passing a tip of the first edge, at least a part of the first radial-directional cross section (S 1) in a blade-height range of 50% or more is inclined downstream in a rotational direction of the impeller with respect to a radial direction, wherein the impeller is configured such that, when a second radial-directional cross section (S 2) is a cross section of the impeller at an axial-directional position passing a tip of the second edge, at least a part of the second radial-directional cross section (S 2) in a blade-height range of 50% or more is inclined upstream in the rotational direction of the impeller with respect to the radial direction, wherein, when, on a second reference line (L 2) connecting midpoints of the second radial-directional cross section (S 2) in a blade thickness direction, a second hub-side reference point (Ph 2) is defined as a radial-directional position of a hub surface of the hub and a second tip-side reference point (Pt 2) is defined as a radial-directional position of the tip, the second-tip side reference point (Pt 2) is positioned upstream of the second hub-side reference point (Ph 2) in the rotational direction, characterized in that the second reference line (L 2) includes a linear portion.