Performance of Jet and Missing Transverse Energy Reconstruction with CMS in pp Collisions at sqrt(s)=7 TeV

\providecommand{\met}{\mbox{${\hbox{${E}$\kern-0.5em\lower-.1ex\hbox{/}}}_T~$}} We present the techniques adopted by CMS to measure the jet energy response and resolutions as well as the Missing Transverse Energy. Results from detailed Monte Carlo studies are compared with preliminary observations from the collider data based on up to 73~nb$^{-1}$ of proton-proton LHC collisions at 7~TeV center of mass energy. Studies for jet energy response and resolutions are presented for three different approaches to reconstruct jets in the CMS detector: calorimeter-only based jet reconstruction, the "Jet-Plus-Track" and the "Particle Flow" method. The studies of the Missing Transverse Energy (\met) reconstruction are based on a data sample of up to $11.7$ $\mbox{nb}^{-1}$ of integrated luminosity. Three missing transverse energy reconstruction algorithms, corresponding to the jet reconstruction approaches, are studied: pure calorimeter~\met, calorimeter~\met corrected with track momenta and~\met calculated using the "Particle Flow" technique. We discuss the cleaning and the performance of these three reconstructions methods using minimum-bias data and data selected to contain high transverse momentum jets.