A new cuff unit for measuring instantaneous blood pressure at the finger based on the volume-compensation method by local pressurization is developed, and its characteristics are evaluated. Results of measurement indicated that, the finger artery could be completely compressed using the local pressurization cuff, and the cuff-pressure controller is suitable for BP measurement in human. Also, the comparative measurements between the present cuff unit and the conventional band-type cuff indicated that, the venous congestion from the present unit is greatly reduced. Therefore, the present cuff unit is capable of non-invasively measuring instantaneous blood pressure at the finger artery in long term.