An EUV light generating apparatus includes: a chamber device including an inner wall surrounding a space, and a plasma generating region in the space in which plasma is generated from a droplet irradiated with a laser beam; a heat shield including a through-hole and a channel portion, and disposed between the inner wall and the plasma generating region; a gas supply device that supplies gas; a gas introducing cylinder that is provided in the space on a side opposite to the plasma generating region, extends toward the through-hole, and introduces the gas supplied from the gas supply device through the through-hole toward the plasma generating region over the heat shield; and an optical unit optically coupled to the space through an internal space of the gas introducing cylinder and the through-hole. An entire front end surface of the gas introducing cylinder faces the heat shield.