Disclosed are an apparatus and method for providing a digital signature. The apparatus includes a certificate unit, an input unit receives a selection input for a certificate related to signature content received from a signature-requesting terminal, and a control unit for determining whether the certificate unit is capable of performing a digital signature function corresponding to a selected certificate. If the certificate unit is capable of performing the digital signature function, the certificate unit creates a digital signature based on a private key corresponding to the selected certificate when the control unit commands the certificate unit to create a digital signature. Further, if the certificate unit is not capable of performing the digital signature function, the control unit creates a digital signature based on a private key corresponding to a certificate selected from the certificate unit. The control unit transmits the digital signature to the signature-requesting terminal.