To provide a new electronic authentication device for authenticating with high reliability.

The electronic authentication device is specified by unique identification data, and comprises an encryption processing means 19 for generating identification data as individual encryption identification data every time the identification data is read from a storage means 18C, an input/output means 20 to an external electronic authentication recording device 34, and an operation mode selecting means 26 for selecting either of sealing operation mode or collating operation mode as an operation mode. When the sealing operation mode is selected, the electronic authentication recording device is authenticated by using the encryption identification data transmitted through the input/output means from the electronic authentication recording device for specifying the electronic authentication recording device, and the encryption identification data of the electronic authentication device, and the encryption identification data of both are housed as an authentication history in the housing means. When the collating operation mode is selected, it is collated whether the electronic authentication recording device is authenticated or not by using both of the encryption identification data on the basis of the authentication history.