Organic semiconductors on metal surfaces are interesting as they might provide a route to realizing the bottom up approach for creating nanometer sized electronic components. In this context, self-assembling systems are of special interest as they provide means for controlling the order at the interface. Phthalocyanines are organic semiconductors with a delocalized π-electron system giving them interesting electronic properties. We have investigated the FePc-Ag(110) interface using synchrotron based photoelectron spectroscopy and low energy electron diffraction. We find that the adsorption of FePc results in an ordered structure with a mixed 3x2/c(6x2) periodicity that changes into a new structure with a more complex symmetry upon thermal treatment to 550 K. Furthermore, this thermal treatment also leads to desorption of the outermost layers resulting in one monolayer (ML) remaining on the surface. Thus a well defined and ordered film can be created at the Ag(110) surface with two different symmetries. The electronic properties of the molecules at the interface is investigated with PES and the Highest Occupied Molecular Orbital (HOMO) of FePc is found at the Fermi level (EF) for thicknesses up to a ML, whereas for thicker films, the HOMO is placed about 0.9 eV below EF. Core level spectroscopy of the film reveals that the shake-up associated with the emission of core photoelectrons is quenched in the ML film due to the metallic substrate whereas it is evident in thicker films. This shows that the electronic properties of thicker films are similar to those found in bulk samples whereas thin films show perhaps more interesting electronic properties.