A drug containing a metal-salen complex compound which is effective for a brain tumor is provided. The present invention is an anti-brain-tumor drug containing a metal-salen complex compound represented by the following Chemical Formula (I). In the formula, M represents a metal atom which is Fe, Cr, Mn, Co, Ni, Mo, Ru, Rh, Pd, W, Re, Os, Ir, Pt, Nd, Sm, Eu, or Gd, and X represents a halogen atom.