The present invention provides an organ production method including a step of tissue-specifically removing a first portion of an organ of a non-human animal partway through development thereof； a step of transplanting, into a region from which the first portion has been removed, an organ precursor cell which is allogeneic or xenogeneic to the non-human animal； and a step of advancing development of the organ, which is a step in which the transplanted organ precursor cell is differentiated and matured to form a part of the organ.
