Abstract
It is the most important issue for the sustainable society to reduce output as disposal and input of natural resource. This paper shows directions of how to reduce the output from public works and the input for public works.
The directions are how to select good ways from various type of recycling. The first is to check from view point of the output of society. The second is to check from view point of the input of society. According to the directions, we found some recycling ways cause increase of the input and/or the output.
