A printing apparatus (2;6), comprising: a discharge head that discharges ink from a nozzle; a recovery tank that stores ink recovered from the discharge head; a supply tank that stores ink to be supplied to the discharge head; a circulation pump that transfers the ink from the recovery tank to the supply tank with supplied electric power to perform an ink circulation operation of circulating ink in a circulation path that returns to the recovery tank after reaching the discharge head from the recovery tank via the supply tank; a first negative pressure applying part configured to apply a negative pressure to the inside of the supply tank; a second negative pressure applying part configured to apply a negative pressure to the inside of the recovery tank; a first solenoid valve provided between the supply tank and the recovery tank, to cut off the supply tank and the recovery tank from each other when being energized and cause the supply tank and the recovery tank to communicate with each other when not being energized; and a power supply part configured to supply electric power to the circulation pump and the first solenoid valve, wherein the second negative pressure applying part has a second solenoid valve connected to the recovery tank, the first negative pressure applying part has a third solenoid valve connected to the supply tank, the first negative pressure applying part further has a first negative pressure pump, and a first negative pressure tank decompressed by the first negative pressure pump and applies a negative pressure generated in the first negative pressure tank by the first negative pressure pump to the supply tank through the third solenoid valve, and the third solenoid valve causes the supply tank and the first negative pressure tank to communicate with each other when being energized and cuts off the supply tank and the first negative pressure tank from each other when not being energized, the second negative pressure applying part further has a second negative pressure pump, and a second negative pressure tank decompressed by the second negative pressure pump and applies a negative pressure generated in the second negative pressure tank by the second negative pressure pump to the recovery tank through the second solenoid valve, the second solenoid valve causes the recovery tank and the second negative pressure tank to communicate with each other when being energized and cuts off the recovery tank and the second negative pressure tank from each other when not being energized. a discharge head that discharges ink from a nozzle; a recovery tank that stores ink recovered from the discharge head; a supply tank that stores ink to be supplied to the discharge head; a circulation pump that transfers the ink from the recovery tank to the supply tank with supplied electric power to perform an ink circulation operation of circulating ink in a circulation path that returns to the recovery tank after reaching the discharge head from the recovery tank via the supply tank; a first negative pressure applying part configured to apply a negative pressure to the inside of the supply tank; a second negative pressure applying part configured to apply a negative pressure to the inside of the recovery tank; a first solenoid valve provided between the supply tank and the recovery tank, to cut off the supply tank and the recovery tank from each other when being energized and cause the supply tank and the recovery tank to communicate with each other when not being energized; and a power supply part configured to supply electric power to the circulation pump and the first solenoid valve, wherein the second negative pressure applying part has a second solenoid valve connected to the recovery tank, the first negative pressure applying part has a third solenoid valve connected to the supply tank, the first negative pressure applying part further has a first negative pressure pump, and a first negative pressure tank decompressed by the first negative pressure pump and applies a negative pressure generated in the first negative pressure tank by the first negative pressure pump to the supply tank through the third solenoid valve, and the third solenoid valve causes the supply tank and the first negative pressure tank to communicate with each other when being energized and cuts off the supply tank and the first negative pressure tank from each other when not being energized, the second negative pressure applying part further has a second negative pressure pump, and a second negative pressure tank decompressed by the second negative pressure pump and applies a negative pressure generated in the second negative pressure tank by the second negative pressure pump to the recovery tank through the second solenoid valve, the second solenoid valve causes the recovery tank and the second negative pressure tank to communicate with each other when being energized and cuts off the recovery tank and the second negative pressure tank from each other when not being energized.