A method of operating a field device

A method of operating a field device (F1) having the field device (F1) settings and / or functions which are divided into different security levels, where by a user (BE) of the settings and / or functions of the field device (F1) is selected, being enabled in response to the level of security of the listening the selected setting and / or function, at least one security measure is executed, wherein it is determined by the safety measure if the selected setting and / or function of the field device (F1) for the user (bE) ,