A target supply device may include a tank for storing a target material, a nozzle which is connected to the tank and outputs the target material, and a gas supply section for supplying the tank with gas. The gas supply section may include a booster which is connected to a gas line, boosts the gas supplied from the gas line, and outputs the boosted gas to the tank, a pressure sensor for measuring the pressure inside the tank, and a pressure controller which adjusts the pressure of the gas to be supplied to the tank on the basis of a measurement result from the pressure sensor.