We report experimental and theoretical evidence that GaGeTe is a basic Z2 topological semimetal with three types of charge carriers: bulkoriginated electrons and holes as well as surface state electrons. This electronic situation is qualitatively similar to the classic 3D topological
insulator Bi2Se3, but important differences account for an unprecedented transport scenario in GaGeTe. High-resolution angle-resolved
photoemission spectroscopy combined with advanced band structure calculations show a small indirect energy gap caused by a peculiar
band inversion at the T-point of the Brillouin zone in GaGeTe. An energy overlap of the valence and conduction bands brings both electron
and holelike carriers to the Fermi level, while the momentum gap between the corresponding dispersions remains finite. We argue that
peculiarities of the electronic spectrum of GaGeTe have a fundamental importance for the physics of topological matter and may boost the
material’s application potential.