  We present the [OIII]52{\mu}m map of the dwarf galaxy IC10, obtained with the
Field-Imaging Far-Infrared Line Spectrometer (FIFI-LS) on board the
Stratospheric Observatory for Infrared Astronomy (SOFIA). We combine the
[OIII]52{\mu}m map with Herschel and Spitzer observations, to estimate the
electron density distribution of the brightest HII regions of IC10. We find
that the line ratio [OIII]88{\mu}m/[OIII]52{\mu}m gives electron density (n_e)
values (n_e_OIII) that cover a broad range, while the n_e values obtained using
the line ratio [SIII]33{\mu}m/[SIII]18{\mu}m (n_e_SIII) are all similar within
the uncertainties. n_e_OIII is similar to n_e_SIII for the M1, M2 and A1
regions, and it is higher than n_e_SIII for the two regions, A2 and M1b, which
are the brightest in the 24{\mu}m continuum emission. These results suggest
that for these regions the two ions, O++ and S++, trace two different ionised
gas components, and that the properties of the ionised gas component traced by
the O++ ion are more sensitive to the local physical conditions. In fact, while
the gas layer traced by [SIII] does not keep track of the characteristics of
the radiation field, the n_e_OIII, correlates with the star formation rate
(SFR), the dust temperature and the 24{\mu}m. Therefore, n_e_OIII is an
indicator of the evolutionary stage of the HII region and the radiation field,
with higher n_e_OIII, found in younger SF regions and in more energetic
environments.
