The attenuated total reflection (ATR) properties and emission light due to surface plasmon (SP) excitations have been investigated in the prism/Ag/MgF2/organic dye/MgF2/Ag structure. Poly(2-methoxy-5-(2 '-ethyl-hexyloxy)-1,4-phenylenevinylene) (MEH-PPV) was used as the organic dye. SPs were excited at the interfaces of Ag/air, Ag/MgF2 and MgF2/Ag in this structure, and the resonant curve due to the SP excitations was observed by the ATR measurement. The emission light through the prism was observed using various light incidences by reverse and usual irradiations. When the incident light angle was fixed to an SP resonant angle as SPs were excited at two interfaces of Ag/MgF2 and MgF2/Ag, the strongest emission light was observed. The emission light spectra at various emission angles were measured and the emission light was related to photoluminescence of the organic dyes, and the intensity and the spectra strongly depended on the emission angles.