An anonymous credential system allows the user to convince a verifier of the possession of a certificate issued by the issuing authority anonymously. One of the applications is the privacy-enhancing electronic ID (eID). A previously proposed anonymous credential system achieves the constant complexity for the number of user's attributes. However, due to the use of RSA-based cryptography, it still suffers from a high cost computation. Recently, we proposed an anonymous credential system with the constant complexity using a pairing-based accumulator, where more efficient ECC (Elliptic Curve Cryptography) can be used instead of the RSA. In this paper, we present an implementation of the anonymous credential system in the application to the eID. We show the practicality of the system from experimental results that the processing times are constantly less than a second.