An extreme ultraviolet light generation system may include a chamber, a first partition wall having at least one opening which provides communication between a first space and a second space, an EUV light concentrating mirror located in the second space and configured to concentrate extreme ultraviolet light generated in a plasma generation region located in the first space, a first gas supply port formed at the chamber, and a gas exhaust port formed in the first partition wall, a distance between the center of the plasma generation region and an edge of the at least one opening being equal to or more than a stop distance LSTOP [mm] calculated by the following equation: LSTOP=272.8·EAVG0.4522·P−1 EAVG [eV] representing average kinetic energy of ions generated in the plasma generation region and P [Pa] representing a gas pressure inside the first partition wall.