The synthetic fiber made from a fossil fuel has the problem of abandonment processing. But lactic acid fiber's polymer, which is the polymer made by starch that can be taken from reproducible vegetable resources. Even if it burns, detrimental gas, such as dioxin, doesn't occur. Moreover, since the microbe in the ground or water decomposes into　carbon dioxide and water when discarded after use, earth environment is not polluted. The produced carbon dioxide is taken in the plant by photosynthesis again, and it is useful to production of starch. Thus, lactic acid fiber's polymer is the ecology material in which natural circulation type recycling is possible and considered earth environment. ・It has feeling of drape and,it has gloss like silk. ・It excels in antibacterial and antimold. ・It is the material of completeness biodegradability which consists of recyclable resources. ・It is the new synthetic fiber of non-petroleum.