  Once all the sleptons as well as the Bino are observed at the ILC, the Bino
contribution to the muon anomalous magnetic dipole moment (muon $g-2$) in
supersymmetric (SUSY) models can be reconstructed. Motivated by the recently
confirmed muon $g-2$ anomaly, we examine the reconstruction accuracy at the ILC
with $\sqrt{s}$ = 500 GeV. For this purpose, measurements of stau parameters
are important. We quantitatively study the determination of the mass and mixing
parameters of the staus at the ILC. Furthermore, we discuss the implication of
the stau study to the reconstruction of the SUSY contribution to the muon
$g-2$. At the benchmark point of our choice, we find that the SUSY contribution
to the muon $g-2$ can be determined with a precision of $\sim 1\%$ at the ILC.
