In the telemedical system securely sharing encryption keys for enabling secure exchange of the encrypted biological data between the measurement terminal and the server to prevent the data from being stolen by the malicious third party, a service key is transferred to the second adapter attached to a measurement terminal from the server via the first adapter attached to the management apparatus. First, the first adapter attached to the management apparatus receives the service key from the server. Next, the first adapter is temporarily detached from the management apparatus and is attached to the measurement terminal to store the symmetric key. The first adapter is detached from the measurement terminal, and is attached to the management apparatus again. The service key received in the first adapter is encrypted using the symmetric key, and the encrypted key is transmitted to the second adapter attached to the measurement terminal.