The present invention relates to a method for efficiently producing a reproducible animal using totipotent cells wherein mitochondrial DNAs (e.g., wild-type DNAs) adapted to nuclear DNAs have been introduced into or substituted with mitochondrial DNAs, and the present invention also relates to an animal obtained by such production method. When the totipotent cells are ES cells derived from an inbred mouse, the tetraploid rescue method is preferably used. In the production of chimeric animals, mitochondrial DNAs of totipotent cells derived from an animal to be used is substituted with wild-type mitochondrial DNAs by the back-crossing method, the nuclear replacement method, or the like, and the cells are injected into a tetraploid fertilized egg, so that a reproducible inbred chimeric animal is produced while avoiding death of the obtained inbred chimeric animal from respiratory disturbances and the like immediately after birth. The thus obtained reproducible chimeric animal can be used for gene function analyses, animal experiments, and the like without carrying out complicated manipulations for generating inbred animals.