PROBLEM TO BE SOLVED: To provide means for efficiently obtaining a mammalian embryo high in conception rate.SOLUTION: One embodiment according to the present invention relates to a method for screening a mammalian embryo having been cultured in vitro from a fertilized egg, the method comprising a step of screening an embryo by making as indexes two or more of: a time from fertilization to completion of first segmentation the form at a stage after the first segmentation and before second segmentation the form at a stage after third segmentation and before fourth segmentation and an amount of oxygen consumption at early stage, middle stage, or external growing stage of the blastocyst.COPYRIGHT: (C)2016,JPO&INPIT【課題】本発明は受胎率が高い哺乳動物胚を効率的に取得するための手段を提供することを目的とする。【解決手段】本発明の第一の形態は、受精卵から体外培養された哺乳動物の胚を選別する方法であって、受精から第一卵割が完了するまでの時間、第一卵割後かつ第二卵割前の段階での形態、第三卵割後かつ第四卵割前の段階での形態、及び、初期胚盤胞期、胚盤胞期又は拡張胚盤胞期での酸素消費量、のうち2つ以上を指標として胚を選別する工程を含む前記方法に関する。【選択図】なし