  LaCuSb$_{2}$ is a superconductor with a transition temperature of about
$T_\text{c} = 0.9$K and is a potential platform where Dirac fermions can be
experimentally observed. In this paper, we report systematic high-resolution
studies of its electronic structure using the angle-resolved photoemission
spectroscopy (ARPES) technique supported by the DFT calculation. The Fermi
surface consists of four branches, of which the two inner ones are more
3-dimensional and the theoretical calculations reproduce well the experiment.
We observe several linear dispersions forming Dirac-like structures. The nodal
lines are present in the system along ${\text{M}}$-${\text{A}}$ and
${\text{X}}$-${\text{R}}$ and Dirac crossings along ${\text{X}}$-${\text{R}}$
are observed by ARPES. Finally, the nesting between external Fermi surface
pockets, which corresponds to charge density wave (CDW) modulation vector is
enhanced in LaCuSb$_{2}$ as compared to LaAgSb$_{2}$, while CDW appears in the
latter system.
