You can confirm the history of basic data manipulation (Waveform filter, Baseline subtraction and Background subtraction) operations which have been performed, and delete operations.
While a spectrum/chromatogram is displayed, select [Processing] in the menu bar and then select [Basic Data Manipulation] > [History] from the drop down menu.
The Processing History dialog appears.
Select the operation to delete and click [Delete].
Click [Delete All] to delete all the operations.