An impeller of a compressor comprising: a disk which rotates about an axis line; and a plurality of blades which are provided at intervals in a circumferential direction at the disk and rotate integrally with the disk, thereby guiding a fluid which flows inward from an axis line direction in which the axis line extends, toward the outside in a radial direction with respect to the axis line, wherein a flow path is formed by the disk along with two surfaces of a pair of blades adjacent to each other, the flow path having an inlet where fluid flows in and an outlet where fluid flows out, and wherein: a root end which is the disk side of the blade and which is connected to the disk is defined as the hub, a tip portion of the blade is defined as the tip, an imaginary curve which is depicted by connecting the middle in a thickness direction of the blade at the tip or an imaginary curve which is depicted by connecting the middle in a thickness direction of the blade at the hub is defined as the center curve, a projection curve is obtained by projecting the center curve in the axis line direction to the disk is defined as the projection curve, a tangential line in the projection curve is defined as the tangential line, a tangential point between the projection curve and the tangential line is defined as the tangential point (Tp), an imaginary straight line orthogonal to a straight line which connects the tangential point (Tp) and the axis line is defined as the imaginary straight line, an angle that the tangential line makes with the imaginary straight line, and which is formed on a rear side in a rotation direction of the disk and an outer periphery side of the disk is defined as the blade angle (β), and the blade angle (β) of the tip of the blade is defined as the first blade angle (β1) and the blade angle (β) of the hub of the blade is defined as the second blade angle (β2), characterized in that the tip has: a constant-tip-angle area in which the first blade angle (β1) is constant from the inlet toward the outlet side, and an increasing-tip-angle area which is continuous with the outlet side of the constant-tip-angle area and in which the first blade angle (β1) gradually increases towards the outlet, wherein the first blade angle (β1) is the largest at the outlet. a disk which rotates about an axis line; and a plurality of blades which are provided at intervals in a circumferential direction at the disk and rotate integrally with the disk, thereby guiding a fluid which flows inward from an axis line direction in which the axis line extends, toward the outside in a radial direction with respect to the axis line, a root end which is the disk side of the blade and which is connected to the disk is defined as the hub, a tip portion of the blade is defined as the tip, an imaginary curve which is depicted by connecting the middle in a thickness direction of the blade at the tip or an imaginary curve which is depicted by connecting the middle in a thickness direction of the blade at the hub is defined as the center curve, a projection curve is obtained by projecting the center curve in the axis line direction to the disk is defined as the projection curve, a tangential line in the projection curve is defined as the tangential line, a tangential point between the projection curve and the tangential line is defined as the tangential point (Tp), an imaginary straight line orthogonal to a straight line which connects the tangential point (Tp) and the axis line is defined as the imaginary straight line, an angle that the tangential line makes with the imaginary straight line, and which is formed on a rear side in a rotation direction of the disk and an outer periphery side of the disk is defined as the blade angle (β), and the blade angle (β) of the tip of the blade is defined as the first blade angle (β1) and the blade angle (β) of the hub of the blade is defined as the second blade angle (β2), characterized in that the tip has: a constant-tip-angle area in which the first blade angle (β1) is constant from the inlet toward the outlet side, and an increasing-tip-angle area which is continuous with the outlet side of the constant-tip-angle area and in which the first blade angle (β1) gradually increases towards the outlet, wherein the first blade angle (β1) is the largest at the outlet. a constant-tip-angle area in which the first blade angle (β1) is constant from the inlet toward the outlet side, and an increasing-tip-angle area which is continuous with the outlet side of the constant-tip-angle area and in which the first blade angle (β1) gradually increases towards the outlet, wherein the first blade angle (β1) is the largest at the outlet.