To provide a novel liquid supply method.Provided is a method for supplying a liquid to an inhaler cartridge including a housing body including an accommodation space capable of accommodating a liquid, a first opening communicating with the accommodation space and opened in a first direction, and a second opening communicating with the accommodation space and opened in a second direction substantially perpendicular to the first direction, and a cap configured to be formed separately from the housing body and close the first opening. The method includes the steps of: closing the first opening with the cap, and after the first opening is closed, supplying the liquid to the accommodation space through the second opening.
