An agitating vessel of an agitator mixing fluid comprising: a body having a hollow inner space so that fluid is stored therein; a rotating unit installed inside the hollow inner space to agitate the fluid; and a horizontal baffle having a plate shape, one end of which is attached to and along an inner wall surface of the hollow inner space of the body and the other end of which is a free end. The plate shape of the baffle is formed in a vertical direction to a central shaft of the rotating unit and in parallel with a bottom surface of the hollow inner space of the body so that two rotations of the fluid are formed above and under the horizontal baffle. The baffle forms a single piece of plate and is extended and attached to the inner wall surface around the central shaft.