The present invention relates to a method of safely and simply inducing differentiation of mononuclear cells into cells that promote neovascular stabilization and maturation, and lead to recovering from ischemia or tissue repair. The cells according to the present invention are obtained by inducing differentiation of a mononuclear cell by culturing the mononuclear cell in a medium (particularly a serum-free medium) containing one or more selected from vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), thrombopoietin (TPO), granulocyte-colony stimulating factor (G-CSF) and FMS-like tyrosine kinase 3 ligand (FLT3L), and collecting a cell population expressing CD11b.