PSI is Switzerland’s largest research centre for the natural sciences and engineering. It conducts top-level research on the subjects of matter and material, people and health, and energy and the environment. By means of fundamental and applied research, it has been working since 1988 on sustainable solutions to central issues arising from society, industry and science. With the Swiss Spallation Neutron Source, the Synchrotron Light Source and the Muon Source, PSI operates large-scale scientific research facilities which are unique in Switzerland; some are even unique worldwide. These facilities are also available to researchers from tertiary institutions and industry. Each year, more than 2,000 researchers come to PSI from around Switzerland and the whole world, for experiments which can only be conducted here. Alongside its research, PSI runs Switz­er­land’s only facility for the treatment of specific cancers with protons.

Around 700 of the approximately 1,500 employment positions at PSI are occupied by scientists. In 2011, around 600 doctoral students took measurements at PSI for their doctoral theses; about 200 are writing their theses within the framework of full-time employment at PSI.

A total of 87 trainees are being taught 13 professions in all. School pupils, students and professionals receive training and continuing education at PSI.

In 2012, PSI is focusing on its future national large-scale facility SwissFEL, an X-ray free-electron laser, which makes it possible to observe brief changes in atomic and molecular structures and is oriented towards the requirements of Swiss research.