In this study, we present the realization of a piezoelectric thin film micro-generator on flexible substrate with an interdigitated electrode structure. The piezoelectric thin films of lead zirconate titanate (PZT) were prepared by a sol-gel process on a flexible metal substrate: a commercial aluminium foil (Al) with a thickness less than 30 μm. Using a photolithography process, we realize the IDE on the surface of the PZT. This structure has the advantage of reducing the linear capacitance of the micro-generator in order to increase the harvested power. However, this makes the electric polarization more difficult because of the voltage to be applied, for inducing the same electric field. To protect the electrode against arcing during the polarization step and improve the adhesion between the PZT and the flexible polymer, an insulating layer of photosensitive resin SU-8 is deposited on its surface. To complete the IDE structure, the aluminium ground plane must be removed from the sample.