An extreme ultraviolet light generating apparatus may include: a chamber, within which extreme ultraviolet light is generated from a droplet which is supplied to a predetermined region therein; an image forming optical system that forms an image of the droplet supplied to the predetermined region; an imaging element that captures an image of the formed image; a stage that moves the image forming optical system and/or the imaging element in an optical axis direction of the image forming optical system; a light energy measuring unit that measures light energy which is generated when the extreme ultraviolet light is generated; and a control unit that controls the stage based on a measured value of the light energy measured by the light energy measuring unit such that an image formation plane of the image of the droplet formed by the image forming optical system matches an imaging surface of the imaging element.