Gas replacement method for liquefied hydrogen pump

A gas replacement method for a liquefied hydrogen pump that is a method for discharging, using a replacement gas, liquefied hydrogen remaining in a liquefied hydrogen pump that sends out liquefied hydrogen, the gas replacement method comprising:

• performing a first purge, the first purge including:
• supplying a hydrogen gas to an inside of the liquefied hydrogen pump;
• and causing the supplied hydrogen gas to push out the liquefied hydrogen to an outside from the inside of the liquefied hydrogen pump;
• and
• performing, after the first purge, a second purge, the second purge including:
• supplying a nitrogen gas to the inside of the liquefied hydrogen pump;
• and causing the supplied nitrogen gas to push out the hydrogen gas to the outside from the inside of the liquefied hydrogen pump.