This command saves the contents of the Peranso Desktop (all Observations Windows, Period Windows and Phase Windows) to a Peranso project file. If no filename has been specified yet by the user, a standard Microsoft Windows File Save dialog box opens up to define the location and filename. 

A Peranso project file can be reopened, using the Open command, at a later stage to continue the data analysis under the same conditions as at the moment of the Save operation.

When saving to an existing Peranso project file, the user will not be prompted again to enter the name of the file. Peranso will simply overwrite that file.