The son of chemist Placidus A. Plattner, he was born in Zürich.
He studied physics at the University of Basel, where he received his doctorate in 1967 and habilitated in 1972.
From 1984 he was an associate professor of experimental physics at the University of Basel.
From 1984 to 1992 he was a member of the Grand Council of the canton of Basel-Stadt.
He later represented the canton of Basel-Stadt in the Senate and served as President of the Council of States (2002-2003).