Using the local spin-density approximation and the 'atom in jellium' model, the size dependences of the electronic structure, ionization potential and photoabsorption cross sections of iron clusters containing up to 130 atoms are obtained. It is shown that the filling of localized atomic d states of iron clusters changes non-monotonically depending on the position of the atom in relation to the cluster surface as well as on the cluster size. The non-monotonic change of the electronic structure with increase of iron cluster size results in the non-monotonic size dependence of the physical properties of the iron cluster presented here.