The dynamics of the ozone formation in an oxygen-fed micro-discharge was st
udied by observing the dispersed emission from the reacting species. The co
rrelation between the ozone production with the physical factors of a micro
-discharge was described by a mathematical model where the distribution of
the mean electronic energy is considered. The results showed that the oxyge
n atom is mostly produced from the oxygen molecule dissociating from the Sc
humann-Runge band, instead of being produced by direct electron bombardment
. This is the reason why pressure has a negative effect role in ozone forma
tion.