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Molecular fluorescence induced by tunneling electrons from a scanning tunneling microscope was investigated for copper phthalocyanine thin films deposited on the highly ordered pyrolytic graphite and the Au(111) substrates. No light emission was observed from the copper phthalocyanine thin films on the highly ordered pyrolytic graphite substrate, on the other hand, the fluorescence of copper phthalocyanine on the Au(111) substrate was observed with plasmon-mediated light emission related to the Au(111) substrate. These results are due to the differences in the charge injection efficiency and surface plasmon resonance mode of two substrates. The obtained fluorescence did not satisfy the quantum cutoff condition, that is, observed photon energy was higher than the energy of injected electrons.