  There are many models beyond the standard model which include electroweakly
interacting massive particles (EWIMPs), often in the context of the dark
matter. In this paper, we study the indirect search of EWIMPs using a precise
measurement of the Drell-Yan cross sections at future $100\,{\rm TeV}$ hadron
colliders. It is revealed that this search strategy is suitable in particular
for Higgsino and that the Higgsino mass up to about $1.3\,{\rm TeV}$ will be
covered at $95\,\%$ C.L. irrespective of the chargino and neutralino mass
difference. We also show that the study of the Drell-Yan process provides
important and independent information about every kind of EWIMP in addition to
Higgsino.
