  Near Ambient Pressure Scanning Photoelectron Microscopy adds to the widely
used photoemission spectroscopy and its chemically selective capability two key
features: (i) the possibility to chemically analyse samples in a more realistic
environmental, gas pressure condition, and (ii) the capability to investigate a
system at the relevant spatial scale. To achieve these goals the approach
developed at the ESCA Microscopy beamline at the Elettra Synchrotron facility
combines the submicron lateral resolution of a Scanning Photoelectron
Microscope with a custom designed Near Ambient Pressure Cell where a gas
pressure up to 0.1 mbar is confined inside it around the sample. In this
manuscript a review of experiments performed with this unique setup will be
presented to illustrate its potentiality in both fundamental and applicative
research such as the oxidation reactivity and gas sensitivity of metal oxides
and semiconductors. In particular the capability to do operando experiment with
this setup opens the possibility to perform investigations with active devices
to properly address the real nature of the studied systems, because it can
yield to more conclusive results when microscopy and spectroscopy are
simultaneously combined in a single technique.
