The positive displacement flow meter has many advantages such as versatility in its application field, high accuracy in measurement with wide ranged flow rate etc. and is now used widely in every industry. In the range of positive displacement flow meters, the rotary flow meter has a particularly simple structure, and ceramic is used as standard material for the bearings which come in contact with liquid. Besides, a special resin excellent in resistance to chemicals. wear, heat and impact is employed for the rotor. A large size legible register is used in the direct totalizer. This rotary flow meter is an easy to use durable liquid flow meter.