A liquid pump comprising: a suction port for sucking a liquid; a pump chamber communicating with the suction port, the pump chamber being defined by a wall, a part of which is a vibrating wall part vibratable to dynamically change a volume of the pump chamber; a discharge-side communicating passage extending from the pump chamber; a discharge-side tank part communicating with the pump chamber through the discharge-side communicating passage to store the liquid delivered from the pump chamber; a discharge-side check valve disposed between the discharge-side tank part and the pump chamber to allow passage of fluid therethrough from the pump chamber toward the discharge-side tank part but prevent passage of fluid therethrough from the discharge-side tank part toward the pump chamber; and a discharge port discharging the liquid from the discharge-side tank part; wherein the liquid is sucked in from the suction port and discharged from the discharge port in response to vibration of the vibrating wall part; the discharge-side tank part having a first inner wall surface and a second inner wall surface facing each other in a horizontal direction in an installed position of the liquid pump, the first inner wall surface being formed with the discharge port, the second inner wall surface being formed with an open end of the discharge-side communicating passage, the discharge-side tank part being configured such that an air pool is formed in a space in the discharge-side tank part above the open end of the discharge-side communicating passage and the discharge port; the liquid pump characterized by: a partition projecting from the second inner wall surface toward the first inner wall surface in the discharge-side tank part at least at a position above the open end of the discharge-side communicating passage so as to cover the open end as seen from the air pool side. a suction port for sucking a liquid; a pump chamber communicating with the suction port, the pump chamber being defined by a wall, a part of which is a vibrating wall part vibratable to dynamically change a volume of the pump chamber; a discharge-side communicating passage extending from the pump chamber; a discharge-side tank part communicating with the pump chamber through the discharge-side communicating passage to store the liquid delivered from the pump chamber; a discharge-side check valve disposed between the discharge-side tank part and the pump chamber to allow passage of fluid therethrough from the pump chamber toward the discharge-side tank part but prevent passage of fluid therethrough from the discharge-side tank part toward the pump chamber; and a discharge port discharging the liquid from the discharge-side tank part; wherein the liquid is sucked in from the suction port and discharged from the discharge port in response to vibration of the vibrating wall part; the discharge-side tank part having a first inner wall surface and a second inner wall surface facing each other in a horizontal direction in an installed position of the liquid pump, the first inner wall surface being formed with the discharge port, the second inner wall surface being formed with an open end of the discharge-side communicating passage, the discharge-side tank part being configured such that an air pool is formed in a space in the discharge-side tank part above the open end of the discharge-side communicating passage and the discharge port; the liquid pump characterized by: a partition projecting from the second inner wall surface toward the first inner wall surface in the discharge-side tank part at least at a position above the open end of the discharge-side communicating passage so as to cover the open end as seen from the air pool side.