The 9 meter long indigenously developed in-line magnetron sputtering system has been used to develop Cr/Au based synchrotron mirror, to be used in the soft X-ray wavelength range of 40-250Å in the PASS beamline at INDUS-1 synchrotron source. Initially Cr/Au films of required thickness have been deposited on small c-Si and zerodour substrates and have been characterized by hard X-ray and soft X-ray reflectivity measurements. The deposition parameters of the sputtering system have been optimized and calibrated for depositing Cr and Au thin films of bulk like density, low surface roughness and a 1% thickness uniformity over a length of 1500 mm. The samples deposited under the optimized condition have been found to yield high soft X-ray reflectivity also in the desired wavelength range. Finally Cr/Au soft X-ray mirrors have been deposited under the above optimized conditions on plane (500 mm X 51 mm X 51 mm) and spheroidal (300 mm X 51 mm X 47 mm) zerodour substrates which will be installed in the PASS beamline soon.