According to the recent hydrogen and methanol economy, the proton conducting materials appear very interesting as an electrolytic membrane and/or an electrode component of fuel cells, CO2/Syngas converters and water steam electrolysers. Prior to the long lifetime requirements their structural and mechanical behaviors as a function of operating condition: high temperature and high water vapor pressure, have to be well determined. Consequently, we designed the autoclave working till 620°C and 50 bars of H2O pressure equipped with a sapphire window allowing in situ Raman scattering measurements. It should be stressed that Raman scattering is an optical technique very efficient to detect both long and short range order structural modifications. The technical and scientific challenges/difficulties encountered during the studies performed on proton conducting zirconates are discussed.