He participated in 1955 and 1956 in the excavations of the sun temple of the 5th Dynasty pharaoh Userkaf at Abusir.
He continued his studies at the University of Heidelberg, where in 1960 he wrote his doctoral thesis on the Syrian-Palestinian deities in Egypt.
He was a technical assistant in Heidelberg until 1967, after which he became scientific director at the German Archaeological Institute in Cairo, where he served from 1989 to 1998.
He participated in numerous excavations at Elephantine, Thebes, and Dahshur; at the latter, he explored and wrote about the Bent Pyramid and the valley temple of King Sneferu.
[3] He also opened a new exhibition at the Egyptian Museum, Cairo, to celebrate 40 years of archaeological work by the Japanese.