Pump device

A pump device contributes to improving the performance of the pump device and suppressing noise and vibration generated in a pump chamber. The pump device comprises a first shell, an impeller and a second shell, the first shell is provided with a fluid inlet and a fluid outlet, and the second shell is overlapped with the first shell from one side in the axial direction to define a pump chamber which accommodates the impeller and is communicated with the fluid inlet and the fluid outlet. The fluid discharge port opens in a direction intersecting the axial direction on a surface of the first housing defining the pump chamber, and the second housing includes an inner peripheral side surface that is close to the first housing in the axial direction and defines the pump chamber, and includes an annular protruding portion that protrudes from an outer peripheral edge of the inner peripheral side surface toward the other side in the axial direction and surrounds the impeller in the circumferential direction. An incli