A waste container throw-in system of a building, comprises a container holder for holding a waste container therein, a handcart for carrying the container holder thereon, a vertical conveyor tube vertically provided in the building, a waste throw-in apparatus including a frame structure and miscellaneous actuators, an inserting tube inserted in the vertical conveyor tube and a central control system for controlling the waste throw-in apparatus. When a collector carries the handcart to the waste throw-in apparatus and couples therewith, the container holder is lifted up from the handcart and moved in the horizontal direction toward the vertical conveyor tube with the help of the actuators. Then, the inserting tube is removed from the vertical conveyor tube and instead thereof the container holder is inserted in the vertical conveyor tube, whereby the waste container is thrown into the vertical conveyor tube. After the waste container is thrown in, the container holder is returned to the handcart and at the same time the inserting tube is inserted in the vertical conveyor tube. These operations are automatically conducted under the control of the central control apparatus of the waste container throw-in system.