To provide a cellulose based coating agent which effectively utilizes a natural resource, enables environmentally friendly waste-disposal or recycling, is inexpensive costwise and is not a completely water-soluble polysaccharide, and has high crystallinity and a molded product having a coating layer which is formed by the coating agent and has an excellent oxygen barrier properties with controlled humidity deterioration and temperature dependency, excels in processability and storability as well, and also has excellent transparency and flexibility.

The coating agent contains a fibrous fine cellulose and the crystallinity of the fine cellulose is within the range of 70-98%, and the fiber breadth of the fine cellulose is within the range of 1 nm-1 μm, and the length of the fine cellulose is within the range of 100-10,000 times the fiber breadth.