  The chemical states of the ZnGeP$_{2}$:Mn interface, which shows
ferromagnetism above room-temperature, has been studied by photoemission
spectroscopy. Mn deposition on the ZnGeP$_2$ substrate heated to 400$^{\circ}$C
induced Mn substitution for Zn and then the formation of metallic Mn-Ge-P
compounds. Depth profile studies have shown that Mn 3$d$ electrons changed
their character from itinerant to localized along the depth, and in the deep
region, dilute divalent Mn species ($\textless$ 5 % Mn) was observed with a
coexisting metallic Fermi edge of non-Mn 3$d$ character. The possibility of
hole doping through Mn substitution for Ge and/or Zn vacancy is discussed.
