While a spectrum/chromatogram is displayed, select [Processing] in the menu bar and then select [Basic Data Manipulation] > [Baseline Subtract] from the drop down menu.
The Baseline Subtract dialog appears.
The Baseline Subtract dialog can also be displayed by clicking the
icon in the toolbar.
Edit the settings.
Click [Apply].
The baseline is displayed on the spectrum/chromatogram. You can check if the settings you have set work as expected.
Click [Subtract].