Ground-based infrared photometric data of Deimos at 4.8, 10, and 20 μm are not consistent with the predictions by the standard thermal model (STM). Contrary to the STM which is a smooth surface model with an artificial beaming factor, this paper attempts to interpret the observations in the framework of a cratered surface model. Heat conduction and the ellipsoidal shape of Deimos are taken into account. The best fit to the observed fluxes is achieved at a relative crater density of 0.9 for nearly hemispherical craters (millimeter to centimeter scale) and a lunar-like heat conduction coefficient of the regolith. The resulting flux ratios observed flux/calculated flux are 0.86, 1.16, and 1.05 at 4.8, 10, and 20 μm, respectively.