The Fe2 molecule is a typical transition metal dimer which has a rather large dissociation energy and a small bond distance compared with the inter-nuclear distance in the crystalline metal. We have investigated the Fe2 molecule with multireference self-consistent-field (MCSCF) and multireference configuration interaction (CI) calculations. The dissociation energy (D(e)), the equilibrium nuclear distance (R(e)), and the zero-point frequency (omega(e)) were calculated (with observed in parentheses) as 1.57 (1.30+/-0.22) eV, 2.06 (1.87 to 2.02) angstrom, and 260.9 (299.6) cm-1, respectively. Thus the agreement between experiment and calculation is very satisfactory, and is a marked improvement on previous theoretical studies. The contribution of the d electrons to the bonding is important and a proper description of correlation effects among the d electrons is indispensable.