An object of the present invention is to provide a means for efficiently obtaining mammalian embryos having high conception rates. A first aspect of the present invention is a method for selecting a mammalian embryo prepared by in vitro culture from a fertilized egg, comprising a step of selecting an embryo using two or more of the following indicators: the time from fertilization to the completion of first cleavage the morphology at a stage after first cleavage and before second cleavage the morphology at a stage after third cleavage and before fourth cleavage and the amount of oxygen consumed at the early blastocyst stage, the blastocyst stage, or the expanded blastocyst stage.
