Laser gas regeneration system and laser system

A laser gas regeneration system for an excimer laser including a first pipe configured to be capable of supplying a laser chamber with a first laser gas, a second pipe configured to be capable of supplying the laser chamber with a second laser gas having a halogen gas concentration higher than a halogen gas concentration of the first laser gas, and a third pipe configured to allow a gas exhausted from the laser chamber to pass therethrough, the laser gas regeneration system comprising:

• a gas refiner that refines the gas having passed through the third pipe;
• a branch that causes a gas having flowed into the gas refiner and having been refined by the gas refiner to divide and flow into a fourth pipe and a fifth pipe;
• a first regenerated gas supplier that supplies the first pipe with a gas having divided and flowed into the fourth pipe;
• and
• a second regenerated gas supplier that adds a halogen gas to a gas having divided and flowed into the fifth pipe and supplies the second pipe with the gas to which the halogen gas has been added.