By using angle-resolved electron spectroscopic methods, we have investigated a monolayer film of hexagonal boron nitride (h-BN) epitaxially formed on Ni(111), Pd(111), and Pt(111). The electronic structure of the monolayer h-BN is almost independent of the substrate, which is in striking contrast with the case of monolayer graphite [A. Nagashima et al., <article>Phys. Rev. B 50, 4756 (1994)</article>]. The comparison of the present data with those for typical physisorbed systems indicates physisorption of the BN film.