Disclosed are semiconductor manufacturing apparatuses and operating methods thereof. The semiconductor manufacturing apparatus includes an oscillation unit that includes a first seed laser, a second seed laser, and a seed module, wherein the first seed laser oscillates a first pulse, and wherein the second seed laser oscillates a second pulse, and an extreme ultraviolet generation unit configured to use the first and second pulses to generate extreme ultraviolet light. The seed module includes a plurality of mirrors configured to allow the first and second pulses to travel along first and second paths, respectively, and a pulse control optical system including a first optical element, a second optical element, and a third optical element. The pulse control optical system is on the second path that does not overlap the first path. The third optical element includes a lens between the first optical element and the second optical element.