  We show the three-dimensional electronic structure of the Kondo lattice CeIn3
using soft x-ray angle resolved photoemission spectroscopy in the paramagnetic
state. For the first time, we have directly observed the three-dimensional
topology of the Fermi surface of CeIn3 by photoemission. The Fermi surface has
a complicated hole pocket centred at the {\Gamma}-Z line and an elliptical
electron pocket centred at the R point of the Brillouin zone. Polarization and
photon-energy dependent photoemission results both indicate the nearly
localized nature of the 4f electrons in CeIn3, consistent with the theoretical
prediction by means of the combination of density functional theory and
single-site dynamical meanfield theory. Those results illustrate that the f
electrons of CeIn3, which is the parent material of CeMIn5 compounds, are
closer to the localized description than the layered CeMIn5 compounds.
