A turbine flowmeter comprises an impeller which has a rotary shaft rotatable together with the impeller and is provided within a flow passage through which a fluid to be measured flows, a pair of bearing members for axially supporting the rotary shaft, an oil accumulating part for holding a lubricating oil therein, and an oil supplying part for supplying the lubricating oil in the oil accomulating part in small quantities to at least one of the bearing members. The oil supplying part comprises a capilary member.