An immersion system includes an immersion tank configured to store a coolant liquid and contain an electronic device, a heat exchanger coupled to the immersion tank through first piping, a first pump provided in the first piping and configured to circulate the coolant liquid between the immersion tank and the heat exchanger, a tank coupled to the immersion tank through second piping, a second pump provided in the second piping and configured to move the coolant liquid between the immersion tank and the tank, a level sensor provided in the immersion tank and configured to detect a liquid level in the immersion tank, and a controller configured to control the second pump in accordance with a detection signal of the level sensor.