A target supply device may include: a target generator configured to accommodate a liquid target material and having a nozzle with a nozzle hole from which the liquid target material is outputted; and a filter disposed in the target generator and made of glass, the glass reacting with the liquid target material, so that a solid reaction product is generated. The filter may include a first through-hole configured to allow the liquid target material to pass therethrough, and an inner surface of the first through-hole may be coated with a material which is not easy to react with the liquid target material.