It is reported that 8-13-micron spectra have been obtained at several positions across the extended emission region of M82. No major differences among the spectra are found. In addition, a strong similarity is found between these spectra and the infrared spectrum of the Orion ionization front. The data are interpreted using a model for M82 in which the Orion nebula is taken as typical of a region of active star formation. A star burst model for M82 is constructed using 100,000 regions similar to Orion. The infrared spectral shape, overall luminosity, radio luminosity, and other observable parameters of M82 are consistent with this model. It is also suggested that models similar to the one proposed here may be used to explain the infrared spectrum of active galactic nuclei such as NGC 1614 and NGC 7469.