In a certificate generating/distributing system, an authentication apparatus includes token transmitting means transmitting, to a service mediating apparatus, a certificate generation request token, which is information corresponding to a first certificate valid in the service mediating apparatus, together with the first certificate. The service mediating apparatus includes mediating apparatus token forwarding means forwarding the certificate generation request token to a service providing apparatus. The service providing apparatus includes certificate requesting means transmitting the certificate generation request token to the authentication apparatus when requesting a second certificate valid in the service providing apparatus. The authentication apparatus includes certificate transmitting means transmitting, to the service providing apparatus, the second certificate generated based on the first certificate in response to the request of the second certificate by the certificate requesting means.