  We present the {\it Spitzer} Space Telescope InfraRed Array Camera (IRAC) and
Multiband Imaging Photometer (MIPS) observations of the elliptical galaxy NGC
315. After removal of the host galaxy's stellar emission, we detected for the
first time an infrared-red nucleus in NGC 315. We measured the spectral energy
distribution (SED) for this active nucleus with wavelength range covering from
radio to X-ray, and obtained the bolometric luminosity of $\rm L_{bol} \approx
1.9 \times 10^{43} ergs s^{-1}$, corresponding to an extremely low Eddington
ratio (L/L$_{\rm Edd}$) of 4.97 $\times$ 10$^{-4}$. Our results confirm that
the physical nature of the nucleus of NGC 315 is a low-luminosity AGN,
consistent with the recent optical and {\it Chandra} X-ray observations.
