A continuous kneading device is provided with an upper trunk (1) to which a powder supply tube (3) through which quantified powder is supplied is connected and in which the powder is blended with a fluid, and a lower trunk (2) concentrically connected to the bottom of the upper trunk (1). The continuous kneading device continuously kneads the powder and the fluid by a first rotating kneading plate (10) built into the upper trunk (1) and a second rotating kneading plate (11) built into the lower trunk (2), wherein surfaces of the base metals of the first and second rotating kneading plates (10, 11) are covered with a coating material (50) for reducing friction when the powder and the fluid are kneaded together.