  We have studied the electronic structure of the diluted magnetic
semiconductor Ga$_{1-x}$Mn$_{x}$N ($x$ = 0.0, 0.02 and 0.042) grown on Sn-doped
$n$-type GaN using photoemission and soft x-ray absorption spectroscopy. Mn
$L$-edge x-ray absorption have indicated that the Mn ions are in the
tetrahedral crystal field and that their valence is divalent. Upon Mn doping
into GaN, new state were found to form within the band gap of GaN, and the
Fermi level was shifted downward. Satellite structures in the Mn 2$p$ core
level and the Mn 3$d$ partial density of states were analyzed using
configuration-interaction calculation on a MnN$_{4}$ cluster model. The deduced
electronic structure parameters reveal that the $p$-$d$ exchange coupling in
Ga$_{1-x}$Mn$_{x}$N is stronger than that in Ga$_{1-x}$Mn$_{x}$As.
