Abstract: A turbine flowmeter comprises a rotor comprising a hub rotatably supported on a shaft at an axial position of a flowmeter housing and a plurality of blades embeddedly fixed to the outer peripheral surface of said hub, means for detecting the rotation of said rotor, and a couple of cone members disposed respectively on the up-stream side and the down-stream side in the flow direction of a fluid being measured to confront at least one surface of the hub of said rotor in coaxial alignment with said rotor. The diameter of at least one cone member of the couple of cone members, at the side to confront said rotor, is larger than outer diameter of the hub of said rotor, whereby a stagnant fluid region is formed between the enlarged diameter part of said cone member and the outer peripheral surface of said hub for holding in stagnant state a part of said fluid being measured.