A method for manufacturing a refilled cartridge for performing refilling of printing material after use of a cartridge is provided. The cartridge includes a first case including a recess having a bottom surface and an opening, a flexible portion attached to the opening, a second case covering the open surface of the first case, a pressure receiving portion contacting the flexible portion, a chamber of variable capacity and a biasing member that generates negative pressure inside the chamber The printing material is refilled into the chamber so that two or more points across the biasing member on the pressure receiving portion do not contact the second case after refilling of the printing material is completed.