  The computation of exclusive QCD jet observables at higher orders requires a
method for the subtraction of infrared singular configurations arising from
multiple radiation of real partons. We present a subtraction scheme relevant
for NNLO perturbative calculations in $e^+e^- \to $ jets. The building blocks
of the scheme are antenna functions derived from the matrix elements for
tree-level $1\to 3$ and $1 \to 4$ and one-loop $1 \to 3$ processes. By
construction, these building blocks have the correct infrared behaviour when
one or two particles are unresolved. At the same time, their integral over the
antenna phase space is straightforward. As an example of how to use the scheme
we compute the NNLO contributions to the subleading colour QED-like
contribution to $e^+e^- \to 3$ jets.
  To illustrate the application of NNLO antenna subtraction for different
colour structures, we construct the integrated forms of the subtraction terms
needed for the five-parton and four-parton contributions to $e^+e^- \to 3$ jets
at NNLO in all colour factors, and show that their infrared poles cancel
analytically with the infrared poles of the two-loop virtual correction to this
observable.
