A polycrystalline diamond film is grown on a 2 inch Si substrate using a microwave-plasma chemicalvapor-deposition technique. The high quality of the diamond films is confirmed by Raman spectra. A multiple-step procedure is used for local etching of the substrate to form the pattern of an array of 50 diamond membranes with the diameter in a range from 150 to 300 μm. The morphology of the membranes is examined using scanning electron microscopy. The membranes obtained can be used as the base material for the fabrication of pressure sensors, X-ray detectors and scintillators, and in quantum optics as optical resonators for single-color centers in diamond.