Abstract: An Object of the present invention is to provide a process for producing a nerve cell by inducing differentiation of an embryonic stem cell, a method for inducing differentiation of the embryonic stem cell into a nerve cell, a medium to be used in the production process or differentiation induction method, or a method for improving purity of the nerve cell obtained by inducing differentiation of the embryonic stem cell. The present invention provides a process for producing a nerve cell which is applicable to treatment of neurodegenerative disease or the like easily, selectively or inexpensively by inducing differentiation induction of an embryonic stem cell using vitamin B12 or a salt thereof and heparin, a substance having heparin-like activity or a salt.