Fichtner was educated in Food Chemistry and Chemistry at the University Karlsruhe, now Karlsruhe Institute of Technology where he was awarded by the Diploma in Chemistry. In 1992 he received the Ph.D. in Chemistry/Surface Science with distinction and the Hermann Billing Award for his thesis. In the thesis he developed a novel method for a spatially resolved speciation of beam-sensitive salts by SIMS. With the method he analysed the surface composition of atmospheric salt aerosol particles and contributed to the current climate model.