The Orion Nebula plays a cornerstone role in our understanding of star formation, as
it hosts the nearest cluster of pre-main-sequence objects spanning the entire range of stellar and substellar
masses. In order to derive the main physical parameters of this unique young population, we
have imaged with the Hubble Space Telescope the entire region from the ultraviolet to the near-infrared. The
Treasury Program on the Orion Nebula, which represents the largest investment of HST
time ever dedicated to star formation, has used in parallel all imagers onboard HST pushing to the limit
the capability of the observatory. I will illustrate the science case, the observational challenges and
strategy, and give an overview of the first scientific results from the survey.