This letter presents the first results of the mid-infrared spectrum (4.5-11.7 /zm) of the diffuse emission near to the galactic plane (I ~ 50°; |ò| < 5°) obtained by the mid-infrared spectrometer on board the Infrared Telescope in Space mission. The results clearly demonstrate the presence of unidentified infrared emission (UIR) bands at 6.2, 7.7, 8.6, and 11.3 /zm in the diffuse galactic emission. The distribution of the UIR bands correlates well with the IRAS 100 jum map, suggesting that the

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... IR-band emitting material is well mixed with the classical dust grains in general interstellar space. The present results indicate that more than 70% of the IRAS 12 /im flux diffuse emission is emitted in the spectral range 8-11.7 /im, and that most of the 12 /im excess comes from the features associated with the UIR bands.