A validation server using HSM, which reduces required process time from receiving a validation request to responding with a validation result, and comprises a first software cryptographic module 142 and a second software cryptographic module 143 on a validation server 130 whose HSM is coupled with an I/F part 148. According to the validation server, load states of HSM, the first software cryptographic module 142 and the second software cryptographic module 143 are monitored by a cryptographic module monitor unit 141, and when cryptographic calculations in a validation process of certificates are conducted, the cryptographic calculations are executed by using the least loaded cryptographic module selected at a cryptographic module selector unit 140.