1. A digital signal coding apparatus for making a compression coding by dividing a digital signal in predetermined transmission units, comprising: an arithmetic coding unit for compressing the digital signal of said transmission unit by arithmetic coding, a binarization unit for generating a binarization rule determined based on a type of coding data; a probability of occurrence generation unit for providing the probability of occurrence of symbol generated by the binarization rule; and a coding unit for arithmetic coding the digital signal of said transmission unit based on the generated probability of occurrence.