A computer implemented method for LSI mask manufacturing stores performance information of a lithography unit, connected to a network, in a lithography unit database. The method receives a lithography data and a lithography reservation condition from a user terminal connected to the network. The method stores the lithography data in a lithography data database. The method searches for a lithography unit matching to the lithography reservation condition, generating a list of lithography units, and sending the list to the user terminal. In addition, the method receives information of a lithography unit specified by the user terminal and sending a lithography request to the lithography unit specified by the user terminal.