An EUV light generator including the following components: A. an electron storage ring including a first linear section and a second linear section; B. an electron supplier configured to supply the electron storage ring with an electron bunch; C. a high-frequency acceleration cavity disposed in the first linear section and configured to accelerate the electron bunch in such a way that a length Lez of the electron bunch satisfies “0.09 m≤Lez≤3 m;” and D. an undulator disposed in the second linear section and configured to output EUV light when the electron bunch enters the undulator.