To reduce the cost required for treatment of leachate by making an equipment necessary for cleaning of the leachate smaller and simpler and making management simpler.

The wastes mainly composed of organic matters obtained by classification are fed into a landfill space 4 and the leachate in this landfill space is recovered from the bottom layer part of a landfill waste layer 6 by a water recovering pipe 7 and is refluxed to the upper layer part by a water release pipe 9. When the landfill space is disposed along a coastline, the sea area along the coastline is cut-off from the inside and the outside by a wall body 2 made of concrete, and particularly at a steep-cliff shore, the landfill space is formed between the wall body 2 built in the form facing an abrasion platform 1 spreading to its sea side or a sea cliff 3 near its offing side and the above sea cliff. Required liner facilities are installed to the strata on the bottom side and the land side.