When a suction button is pushed in a pushing operation direction, the suction button pushes down longer lever ends of inversion levers, shorter lever ends of the inversion levers are pushed up based on a seesaw operation and the principle of leverage, and a piston body coupled through a coupling body moves in a direction opposed to a pushing operation direction against an urging force of a spring in cooperation with this upward movement. As a result, a valve moving portion moves away from a valve receiving portion to open a suction duct valve portion and suction is carried out, but the piston body retires to an outer periphery side of a bent duct when the valve portion is opened, and hence a suction duct is widened, thereby facilitating suction of even, e.g., a fluid having high viscosity.