A pump device (10, 110, 210, 310), comprising: a motor portion (20, 120, 220) having a shaft (41, 141, 241) having its center on an axially extending center axis, a rotor which is fixed to the shaft (41, 141, 241), and a stator which is disposed on a radially outer side of the rotor; a pump portion (30, 230, 330) which is disposed on one axial side of the motor portion (20, 120, 220), and driven by the motor portion (20, 120, 220); a cylindrical housing which holds the motor portion (20, 120, 220) and the pump portion (30, 230, 330), and has an opening portion on the other axial side; and a motor cover which is attached to the other axial side of the housing, and covers the other axial side of the motor portion (20, 120, 220), the motor portion (20, 120, 220) including: a sensor magnet which is disposed on the other axial side from the stator, and fixed to an outer circumferential surface of the shaft (41, 141, 241); a bus bar unit disposed in the opening portion; a circuit board which is held by the bus bar unit; and a rotation sensor which is attached to the circuit board, and axially faces the sensor magnet, the bus bar unit having a bus bar which is electrically connected to the rotation sensor and a bus bar holder which holds the bus bar, the bus bar holder having a cylindrical holder main body portion which is disposed on a radially inner side of the opening portion, the pump portion (30, 230, 330) including: an inner rotor which is attached to the shaft (41, 141, 241); an annular outer rotor which surrounds a radially outer side of the inner rotor; a pump body which accommodates the inner rotor and the outer rotor; and a pump cover (32, 232, 332) which is attached to one axial side of the pump body, wherein the circuit board has a circuit board through-hole which axially penetrates the circuit board, and the center axis of the shaft (41, 141, 241) passes through the center of said through-hole, and an end portion on the other axial side of the shaft (41, 141) is provided with a connection portion (41b, 141c) which is connectable to another member. a motor portion (20, 120, 220) having a shaft (41, 141, 241) having its center on an axially extending center axis, a rotor which is fixed to the shaft (41, 141, 241), and a stator which is disposed on a radially outer side of the rotor; a pump portion (30, 230, 330) which is disposed on one axial side of the motor portion (20, 120, 220), and driven by the motor portion (20, 120, 220); a cylindrical housing which holds the motor portion (20, 120, 220) and the pump portion (30, 230, 330), and has an opening portion on the other axial side; and a motor cover which is attached to the other axial side of the housing, and covers the other axial side of the motor portion (20, 120, 220), the motor portion (20, 120, 220) including: a sensor magnet which is disposed on the other axial side from the stator, and fixed to an outer circumferential surface of the shaft (41, 141, 241); a bus bar unit disposed in the opening portion; a circuit board which is held by the bus bar unit; and a rotation sensor which is attached to the circuit board, and axially faces the sensor magnet, a sensor magnet which is disposed on the other axial side from the stator, and fixed to an outer circumferential surface of the shaft (41, 141, 241); a bus bar unit disposed in the opening portion; a circuit board which is held by the bus bar unit; and a rotation sensor which is attached to the circuit board, and axially faces the sensor magnet, the bus bar unit having a bus bar which is electrically connected to the rotation sensor and a bus bar holder which holds the bus bar, the bus bar holder having a cylindrical holder main body portion which is disposed on a radially inner side of the opening portion, the pump portion (30, 230, 330) including: an inner rotor which is attached to the shaft (41, 141, 241); an annular outer rotor which surrounds a radially outer side of the inner rotor; a pump body which accommodates the inner rotor and the outer rotor; and a pump cover (32, 232, 332) which is attached to one axial side of the pump body, an inner rotor which is attached to the shaft (41, 141, 241); an annular outer rotor which surrounds a radially outer side of the inner rotor; a pump body which accommodates the inner rotor and the outer rotor; and a pump cover (32, 232, 332) which is attached to one axial side of the pump body, wherein the circuit board has a circuit board through-hole which axially penetrates the circuit board, and the center axis of the shaft (41, 141, 241) passes through the center of said through-hole, and an end portion on the other axial side of the shaft (41, 141) is provided with a connection portion (41b, 141c) which is connectable to another member.