To solve the problem that the conventional method for, e.g. improving contaminated soil of agricultural land, contaminated ground, or the like requires much time for one time and keeps the mixing and stirring unconstant each time because the constant amount of soil is charged into a mixer, or the like and repeatedly mixed and stirred many times until the soil becomes uniform, and that the work is interrupted to result in inefficiency also because the soil is transferred from the mixer to the other transportation means after the mixing and stirring.

In an apparatus for uniformly stirring and mixing multiple kinds of conveying articles to continuously convey and supply the set amount of articles, the upper position of the conveyor apparatus which is provided so as to continuously convey the set amount of conveying articles by rotatably driving a coil spring-like conveyor is provided with a plurality of charging and supplying ports for continuously and separately charging and supplying the set amount of various kinds of conveying articles such as contaminated soil or soil improving agent. The vicinity of the end part is provided with a discharge port for discharging the mixed conveyed articles to the outside.