To provide a precipitate transfer device of a good efficiency wherein the costs of power and water can be extremely reduced.

A suction opening 11a open to an under bottom part of a wastewater treatment pond is provided to one end, and a discharge opening 12a dipped in water of the wastewater treatment pond is provided to the other end. A transfer pipe line 13 wherein a gravity classifier 14 for separating a precipitate in the wastewater into sieve residue and sedimentation sand and removing them and a circulation pump 15 are successively interposed from the suction opening side 11a to the discharge opening side, and a degassing means for degassing in the gravity classifier 14 and in the transfer pipe line 13 are provided midway. The degassing means is started, and the insides of the gravity classifier 14 and the transfer pipe line 13 are degassed. Thereby, a syphon is formed, and the inside of the gravity classifier 14 and the inside of the transfer pipe line 13 are filled with wastewater. Thereafter, the circulation pump 15 is started, and the precipitate is transferred together with the wastewater from the suction opening 11a to be gravity classifier 14.