Problem to be Solved The object of the present invention is to provide a method for culturing a regenerated tooth germ so that the shape of the tooth is not restricted by pressure or space even when cultured in vivo and the extension of the tooth can also be controlled. It is also an object to provide a method which allows transplantation of a regenerated tooth even when the missing tooth site is large. Solution The present invention provides a method for manufacturing a regenerated tooth unit comprising a step of disposing and culturing a regenerated tooth germ inside a spacer in vivo in the body of a mammal, wherein said spacer is configured so as to enable prevention of excessive pressure being applied to said regenerated tooth germ from a tissue inside the body of said mammal, and prevention of said regenerated tooth germ being extended to more than the maximum tolerance； and configured such that the regenerated tooth germ disposed inside is communicatable with the exterior of the spacer. A method for manufacturing a regenerated tooth unit comprising a step of disposing and culturing multiple regenerated tooth germs inside a spacer in vivo in the body of a mammal is also provided.
