To increase conveying force of excavated sediment in earth discharge pipes.

An earth discharge device for a tunnel excavator such as a shield machine or a small bore pipe propulsion machine is provided with a screw conveyor 6 installed in an excavator body, earth discharge pipes 10a, 10b connected to the rear, lower part or rear end of the screw conveyor 6, a vacuum device connected to the rear ends of the earth discharge pipes 10a, 10b, and intake ports 12 provided at the earth discharge pipes 10a, 10b. In this case, compressed air blowoff ports 15a-15c are provided near the inlets of the earth discharge pipes 10a, 10b.