A variable capacity vane pump having a rotation axis, comprising: a pump housing comprising a high-load bearing part to which a higher load is exerted than another part when the vane pump operates; a control valve which regulates a pressure supplied to the vane pump for varying a capacity thereof; a valve housing which is formed in the pump housing on an identical side of the high-load bearing part in a radial direction with respect to the rotation axis to accommodate the control valve; a rotor formed into a cylindrical body having an end face and accommodated in the pump housing, the rotor having a center axis which corresponds to the rotation axis and a plurality of vanes which protrude radially from an outer periphery thereof, each of the vanes having a protruding tip; a cam ring that is supported in the pump housing to surround the rotor in an eccentric position thereto and contacts the protruding tips of the vanes so as to form pump chambers delimited by the vanes, the pump chambers comprising high-pressure pump chambers and low-pressure pump chambers which are defined in relation to a rotation position of the rotor about the center axis; the higher load being derived from a pressure in the high-pressure pump chambers; an end plate fixed in the pump housing so as to face the end face of the rotor, the end plate having a discharge port facing the high-pressure pump chambers, wherein the valve housing is formed in an offset position from the high-pressure pump chambers along the center axis of the rotor; and the control valve comprises a valve body in a shape of a spool having an axis, and the valve housing is formed such that the axis of the valve body is orthogonal to the center axis of the rotor; characterized in that the pump housing further comprises a pair of reinforcing ribs (24, 25) formed on an outer periphery of the high-load bearing part in parallel with the center axis of the rotor. a pump housing comprising a high-load bearing part to which a higher load is exerted than another part when the vane pump operates; a control valve which regulates a pressure supplied to the vane pump for varying a capacity thereof; a valve housing which is formed in the pump housing on an identical side of the high-load bearing part in a radial direction with respect to the rotation axis to accommodate the control valve; a rotor formed into a cylindrical body having an end face and accommodated in the pump housing, the rotor having a center axis which corresponds to the rotation axis and a plurality of vanes which protrude radially from an outer periphery thereof, each of the vanes having a protruding tip; a cam ring that is supported in the pump housing to surround the rotor in an eccentric position thereto and contacts the protruding tips of the vanes so as to form pump chambers delimited by the vanes, the pump chambers comprising high-pressure pump chambers and low-pressure pump chambers which are defined in relation to a rotation position of the rotor about the center axis; the higher load being derived from a pressure in the high-pressure pump chambers; an end plate fixed in the pump housing so as to face the end face of the rotor, the end plate having a discharge port facing the high-pressure pump chambers, wherein the valve housing is formed in an offset position from the high-pressure pump chambers along the center axis of the rotor; and the control valve comprises a valve body in a shape of a spool having an axis, and the valve housing is formed such that the axis of the valve body is orthogonal to the center axis of the rotor; characterized in that the pump housing further comprises a pair of reinforcing ribs (24, 25) formed on an outer periphery of the high-load bearing part in parallel with the center axis of the rotor.