To provide a Mores code detecting device whose performance can be improved as compared to a conventional one.

The Mores code receiving device is equipped with a code judging unit 25 for judging a code based on a code judging threshold value for performing code judgment of which type of a code new input codes comprising Mores codes are, a representative value updating unit 26 for updating a given type code length representative value showing a representative value of a code length of a given type, and a threshold value updating unit 27 for updating a code judging threshold value based on a given type code length representative value updated by the representative value updating unit 26. The representative value updating unit 26 updates the given type code length representative value of the code of the type judged by the code judging unit 25 based on the new input code length.