  We perform a feasibility study of a beam dump experiment at the International
Linear Collider (ILC). To investigate the sensitivity to new light particles at
the experiment, we consider models for axion-like particles (ALPs) and a light
scalar particle coupled to charged leptons. For both models, we show that the
detection sensitivity is almost an order of magnitude higher than other beam
dump experiments in the small coupling region. For ALPs, it is shown that the
ILC beam dump experiment is highly complementary to bounds from astrophysics.
In addition, for the model of the scalar particle, the region favored by the
muon $g-2$ experiment can be explored.
