A target generation device according to one aspect of the present disclosure includes a tank for containing a target substance, a heater provided at the tank, a nozzle communicating with the inside of the tank, a lid having a gas inlet port communicating with the inside of the tank, and a plurality of shielding plates that are disposed inside the tank and suppress entry of the target substance to the gas inlet port. Each of the shielding plates includes at least one non-shielding region for allowing the gas to pass through. The non-shielding regions of at least two of the shielding plates are arranged at positions in which one of the non-shielding regions of the at least two of the shielding plates is not seen into the other of the non-shielding regions of the at least two of the shielding plates.