An extreme ultraviolet light generating apparatus may include a chamber including a window to allow first and second pulse laser beams to enter, a mirror to reflect the first pulse laser beam, a first actuator to control a position or a posture of the mirror, a beam combiner to cause optical paths of the first and second pulse laser beams to substantially coincide with each other, a reflective optical system to reflect the first and second pulse laser beams from the beam combiner, a second actuator to control a position or a posture of the reflective optical system, sensors each configured to output data for detecting a position of an optical path of the first pulse laser beam, and a controller to control the first actuator based on the data and control the second actuator based on a value related to control of the first actuator.