A remanufacturing method of remanufacting a process cartridge includes (a) a step of preparing a used process cartridge which comprises a toner developing container, a cleaning container and pins for coupling the toner developing container and the cleaning container at opposite longitudinal ends of the process cartridge; the toner developing container including a toner accommodating portion, a toner supply opening, a developing roller and a developing blade; the cleaning container including an electrophotographic photosensitive drum; (b) a container separating step of separating the process cartridge into the toner developing container and the developing container by disengaging the pins from the process cartridge; (c) a developing roller dismounting step of dismounting the developing roller from the toner developing container separated by the container separating step; (d) a developing blade dismounting step of dismounting the developing blade from the toner developing container separated by the container separating step; (e) an elastic member mounting step of mounting an elastic member to a longitudinally inside of an end seal provided adjacent each of opposite longitudinal ends of a or the developing roller, at a position laterally outside of the end seal; (f) a developing blade mounting step of mounting a or the developing blade on a or the toner developer container; (g) a developing roller mounting step of mounting a or the developing roller on the toner developer container having the developing blade; (h) a toner refilling step of refilling the toner into a or the toner accommodating portion of the toner developing container having the developing blade and the developing roller; and (i) a container coupling step of coupling the toner developing container having the developing blade and the developing roller with a or the cleaning container by engaging a or the pin into them.