  We present here a model for simulating the panchromatic spectral energy
distribution of galaxies, which aims to be a complete tool to study the complex
multi-wavelength picture of the universe. The model take into account all
important components that concur to the SED of galaxies at wavelengths from
X-rays to the radio. We review the modeling of each component and provide
several applications, interpreting observations of galaxy of different types at
all the wavelengths.
