  We have imaged $\epsilon$ Indi B, the closest brown dwarf binary known, with
VISIR at the VLT in three narrow-band mid-infrared bandpasses located around
8.6$\mu$m, 10.5$\mu$m and 11.3$\mu$m. We are able to spatially resolve both
components, and determine accurate mid-infrared photometry for both components
independently. In particular, our VISIR observations probe the NH$_3$ feature
in the atmospheres of the cooler and warmer brown dwarfs. For the first time,
we can disentangle the contributions of the two components, and find that % our
photometry of $\epsilon$ IndiBb is in good agreement with recent ``cloud-free''
atmosphere models having an effective temperature of $T_\mathrm{eff}=800$ K.
With an assumed age of 1 Gyr for the $\epsilon$ Indi system, component Ba
agrees more with $T_\mathrm{eff} \approx 1100$ K rather than with
$T_\mathrm{eff}=1200$ K, as suggested by SPITZER spectroscopic observations of
the combined $\epsilon$ Indi B system (Roellig et al., 2004). Even higher
effective temperatures appear inconsistent with our absolute photometry, as
they would imply an unphysical small size of the brown dwarf $\epsilon$ IndiBa.
