A flow meter for measuring a flow rate of fluid includes a body providing a main passage through which the fluid flows. A plurality of support elements connect an inner wall surface of the body and a central element so as to support the central element substantially at the center of the main passage. An introducing port opens to the central element for introducing a part of the fluid flowing through the main passage. A branch passage is formed within the central element, through which such part of the fluid flows. A sensor is disposed within the branch passage for measuring a flow rate within the branch passage. An outlet opens to a portion of the central element located at upperstream of the downstream ends of the support elements for returning the fluid flowing through the branch passages to the main passage.