Filling method

A filling method comprising:

• storing liquid in a liquid tank;
• pressing a seal member of a filling head against a mouth of a vessel to seal the mouth of the vessel by the seal member;
• providing a liquid valve in a liquid passageway which connects an inside of the liquid tank to the vessel via the filling head;
• providing a gas valve in a gas passageway connecting a headspace of the liquid tank to the vessel via the filling head;
• providing a snifting valve in a snifting passage which connects the vessel to an outside via the filling head;
• detecting an amount of the liquid supplied to the vessel;
• and
• when the liquid is a non-fizzy liquid, opening the liquid valve to supply the liquid to the vessel while a compressor pressurizes the inside of the liquid tank, while the gas valve is closed, while the snifting valve is opened, and while the mouth of the vessel is sealed by the seal member.