  The performance of the ILD detector at the ILC for the analysis of $\mu$ and
$\tau$ channels at the SUSY benchmark-point SPS1a' has been studied with full
detector simulation. It is concluded that if 500 fb$^{-1}$ is delivered to the
experiment, $\Delta(\MXN{1}) = 920 \MeVcc$, $\Delta(\msmul) = 100 \MeVcc$,
$\Delta(\MXN{2}) = 1.38 ~\GeVcc$, and $\Delta(\sigma(\eeto \smul \smul))$ =
1.35 fb can be achieved from the $\mu$ channels alone. The preliminary results
from the $\stau$ channels, indicates that $\Delta(P_{\tau}) = 13 $ % is also
achievable.
