Continuously charging silver nitrate solution and alkali halide solution into one tank, the produced emulsion was discharged continuously by overflowing. The tank was made of Cr-Ni-Mo-steel, and was covered by the insulater. The electric wire heater was wound around it. The polyethylene pipe and a special plunger pump with ball valves was employed to transport the liquid. A constant volume of emulsion was maintained in the tank. When the constant volume of emulsion in the tank was V and the charging amount during unit time was F , the following fact was certified: As the value of V/F was smaller, the old emulsion was discharged sooner, the ripening time distribution was smaller, the silver halide particles were smaller and more uniform and the gamma of emulsion was larger. The agitation was done by blowing air or by the rotor rotated in magnetic field as well as a customary propeller agitation.