This study examines how traditional knowledge functions in the specific techniques to make pottery in terms of the traditional knowledge on the pottery techniques of Onggi potters. It focuses on how traditional pottery manufacturing skills are categorized and what aspects are observed with regard to the techniques. The pottery manufacturing process is divided into the preparation step of raw material, the molding step of pottery, and the final plasticity step. Each step involves unique traditional knowledge. The preparation step mainly comprises the knowledge on different kinds of mud. The knowledge is about the colors and properties of mud, the information on the regional distribution of quality mud, and the techniques to optimize mud for pottery manufacturing. The molding step mainly involves the structure and shape of spinning wheels, the techniques to accumulate mud, ways to use different kinds of tools, the techniques to dry processed pottery. The plasticity step involves the knowledge on kilns and the scheme to build kilns, the skills to stack pottery inside of the kilns, the knowledge on firewood and efficient ways of wood burning, the discrimination of different kinds of fire and the techniques to stoke the kilns. These different kinds of knowledge may be roughly divided into three categories : the preparation of raw material, molding, and plasticity. They are closely connected with one another, which is because it becomes difficult to manufacture quality pottery even with only one incorrect factor. The contents of knowledge involved in the manufacturing process of pottery focused are mainly about raw material, color, shape, distribution aspect, fusion point, durability, physical property, etc, which are all about science. They are rather obtained through the experimental learning process of apprenticeship, not through the official education. It is not easy to categorize the knowledge involved. Most of the knowledge can be understood in the category of ethnoscience. In terms of the UNESCO world heritage of intangible cultural assets, the knowledge is mainly about 'the knowledge on nature and universe'. Unique knowledge and skills are, however, identified in the molding step. They can be referred to 'body techniques', which unify the physical stance of potters, tools they employ, and the conceived pottery. Potters themselves find it difficult to articulate the knowledge. In case stated, it cannot be easily understood without the experience and knowledge on the field. From the preparation of raw material to the complete products, the techniques and traditional knowledge involved in the process of manufacturing pottery are closely connected, employing numerous categories and levels. Such an aspect can be referred to as a 'techniques chain'. Here the techniques mean not only the scientific techniques but also, in addition to the skills, the knowledge of various techniques and levels including habitual, unconscious behaviors of potters.