To provide a screw type excavator having a screw shorter than the depth of an excavation hole, saving power, and conducting the good-efficiency excavation work by reducing the resistance of mud when lifting the screw as mud is accumulated on the upper part of the screw inside the excavation hole.

The screw 10 and a rod 9 are connected so that the sum of the connected length corresponds to the depth of the aimed excavation hole. A stirring section 20 having a soil stirring function is provided near the upper end of the screw 10, and the screw 10 is lifted while the soil accumulated on the screw 10 is fluidized by the stirring section 20.