Method for initialising a server (15, 16) embodied as an operator station in a technical installation, in particular production or process installation, wherein the technical installation has at least one server embodied as an engineering station and at least one certification authority (20, 23) for issuing certificates, the method comprising the following steps: a) Establishment of a connection from the engineering station server to the operator station server (15, 16); b) Installation of a trust chain (5, 6) valid for the engineering station server on the operator station server (15, 16); c) Installation of a trust chain (5, 6) valid for the operator station server (15, 16) on the engineering station server; d) Transmission of a validation certificate of the engineering station server to the operator station server (15, 16) so that the operator station server (15, 16) can validate the engineering station server by means of the corresponding trust chain (5, 6) previously installed; e) Transmission of a validation certificate of the operator station server (15, 16) to the engineering station server so that the engineering station server can validate the operator station server (15, 16) by means of the corresponding trust chain (5, 6) previously installed; f) Transmission of configuration information from the engineering station server to a certification service (37, 38) implemented on the operator station server (15, 16), wherein the configuration information depends on a role of the operator station server (15, 16) in the technical installation and comprises information as to which certificates of the certification service (37, 38) of the operator station server (15, 16) must be requested from the certification authority (20, 23) of the technical installation. a) Establishment of a connection from the engineering station server to the operator station server (15, 16); b) Installation of a trust chain (5, 6) valid for the engineering station server on the operator station server (15, 16); c) Installation of a trust chain (5, 6) valid for the operator station server (15, 16) on the engineering station server; d) Transmission of a validation certificate of the engineering station server to the operator station server (15, 16) so that the operator station server (15, 16) can validate the engineering station server by means of the corresponding trust chain (5, 6) previously installed; e) Transmission of a validation certificate of the operator station server (15, 16) to the engineering station server so that the engineering station server can validate the operator station server (15, 16) by means of the corresponding trust chain (5, 6) previously installed; f) Transmission of configuration information from the engineering station server to a certification service (37, 38) implemented on the operator station server (15, 16), wherein the configuration information depends on a role of the operator station server (15, 16) in the technical installation and comprises information as to which certificates of the certification service (37, 38) of the operator station server (15, 16) must be requested from the certification authority (20, 23) of the technical installation.