A flow regulating apparatus comprising: a valve body section where a projection portion is provided at a distal end; a main body section where a valve chamber and an air introduction port are formed, the valve chamber being formed so as to house the valve body section, the air introduction port being formed so as to introduce compressed air from outside; a valve hole that allows the projection portion to be inserted therein, and brings an inflow channel for a fluid and the valve chamber into communication with each other; a flow regulating mechanism (3, 10, 13, 19) that adjusts an insertion amount of the projection portion into the valve hole to regulate a flow rate of a fluid flowing into the valve chamber from the valve hole; a piston section that is coupled to the valve body section, and is movable in the direction of a center axis (c) of the valve body section; and a spring section that gives a first urging force in a direction to bring the valve body section close to the valve hole via the piston section, wherein the flow regulating mechanism (3, 10, 13, 19) includes a knob section (3, 19) that rotates around a center axis of the valve body section according to an operation by an operator, and is fixed at a given position irrespective of rotation around the center axis, a rod member that extends along the center axis, and adjusts the insertion amount by moving in a direction of the center axis, a pin member that is fixed to the knob section (3, 19), and extends in a direction substantially perpendicular to the center axis, and a moving member that is arranged coaxially with the valve body section, the moving member being a cylindrical shape, the rod member including a first threaded portion that is fastened to a body-side threaded portion formed on an inner circumferential surface of the main body section, a second threaded portion that is fastened to a moving member threaded portion formed on an inner circumferential surface of the moving member at a distal end portion closer to the valve hole than the first threaded portion, and a through hole penetrating in the direction substantially perpendicular to the center axis and having a predetermined width according to a moving range of the valve body section in the direction of the center axis, the pin member is inserted into the through hole, and rotates around the center axis together with the knob section (3, 19) in response to the operation of the knob section (3, 19) by the operator, a second urging force in a direction to bring the valve body section away from the valve hole is generated on the valve body section via the piston section by the compressed air introduced into a pressure chamber in communication with the air introduction port, the moving member and the piston section are separated from each other when the first urging force exceeds the second urging force, and the moving member and the piston section come into contact with each other when the second urging force exceeds the first urging force, and the piston section and the moving member are restricted by a restriction member so as not to relatively rotate around the center axis, the restriction member being arranged in contact with the piston section and the moving member. a valve body section where a projection portion is provided at a distal end; a main body section where a valve chamber and an air introduction port are formed, the valve chamber being formed so as to house the valve body section, the air introduction port being formed so as to introduce compressed air from outside; a valve hole that allows the projection portion to be inserted therein, and brings an inflow channel for a fluid and the valve chamber into communication with each other; a flow regulating mechanism (3, 10, 13, 19) that adjusts an insertion amount of the projection portion into the valve hole to regulate a flow rate of a fluid flowing into the valve chamber from the valve hole; a piston section that is coupled to the valve body section, and is movable in the direction of a center axis (c) of the valve body section; and a spring section that gives a first urging force in a direction to bring the valve body section close to the valve hole via the piston section, a knob section (3, 19) that rotates around a center axis of the valve body section according to an operation by an operator, and is fixed at a given position irrespective of rotation around the center axis, a rod member that extends along the center axis, and adjusts the insertion amount by moving in a direction of the center axis, a pin member that is fixed to the knob section (3, 19), and extends in a direction substantially perpendicular to the center axis, and a moving member that is arranged coaxially with the valve body section, the moving member being a cylindrical shape,