Amyotrophic lateral sclerosis (ALS) is an intractable neurodegenerative disease, and no fundamental treatment has yet been developed for sporadic patients. Therefore, there are high expectations for regenerative therapies, mainly cell therapy. We have been developing a treatment that applies autologous bone marrow cells that can be autotransplanted. In this chapter, we introduce the details of the method for inducing autologous bone marrow cells to become microglia-like cells, which were named bone marrow-derived inducible microglia-like (BM-iMG) cells with neuroprotective effects, the method of administering them to model animals, and evaluating their effects.