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AIMS: To investigate the very high energy (VHE: >100 GeV) gamma-ray emissionfrom the high-frequency peaked BL Lac 1ES 0229+200.  METHODS: Observations of 1ES 0229+200 at energies above 580 GeV wereperformed with the High Energy Stereoscopic System (HESS) in 2005 and 2006.  RESULTS: 1ES 0229+200 is discovered by HESS to be an emitter of VHE photons.A signal is detected at the 6.6 sigma level in the HESS observations (41.8 hlive time). The integral flux above 580 GeV is (9.4 +- 1.5 {stat} +- 1.9{syst}) x 10^{-13} cm^{-2} s^{-1}, corresponding to ~1.8% of the flux observedfrom the Crab Nebula. The data show no evidence for significant variability onany time scale. The observed spectrum is characterized by a hard power law(Gamma = 2.50 +- 0.19 {stat} +- 0.10 {syst}) from 500 GeV to ~15 TeV.  CONCLUSIONS: The high-energy range and hardness of the observed spectrum,coupled with the object's relatively large redshift (z=0.1396), enable thestrongest constraints so far on the density of the Extragalactic BackgroundLight (EBL) in the mid-infrared band. Assuming that the emitted spectrum is notharder than Gamma_{int} ~ 1.5, the HESS data support an EBL spectrum ~lambda^{-1} and density close to the lower limit from source counts measured bySpitzer, confirming the previous indications from the HEGRA data of 1ES1426+428 (z=0.129). Irrespective of the EBL models used, the intrinsic spectrumof 1ES 0229+200 is hard, thus locating the high-energy peak of its spectralenergy distribution above a few TeV.

New constraints on the Mid-IR EBL from the HESS discovery of VHE gamma rays from 1ES 0229+200