  We report on the fabrication and characterization of a two-terminal
mesoscopic interferometer based on three V/Cu/V Josephson junctions having
nanoscale cross-section. The junctions have been arranged in a double-ring
geometry realized by metallic thin film deposition through a suspended mask
defined by electron beam lithography. Although a significant amount of
asymmetry between the critical current of each junction is observed we show
that the interferometer is able to suppress the supercurrent to a level lower
than 6 parts per thousand, being here limited by measurement resolution. The
present nano-device is suitable for low-temperature magnetometric and
gradiometric measurements over the micrometric scale.
