The Fermi bubbles are two gamma-ray lobes extending up to 55 degrees above and below the
Galactic center. The Fermi bubbles, in contrast to lobes in other galaxies, were
discovered in gamma rays, rather than radio waves or X-rays, which makes them both
unique and interesting to study. We have analyzed 50 months of the Fermi LAT data (Pass
7 reprocessed) to study in detail the spectrum and morphology of the bubbles. In the
talk, I will explain the gamma-ray data analysis, including the estimation of systematic
uncertainty related to modeling of Galactic gamma-ray foreground emission. I will talk
about interpretation of the bubbles in terms of leptonic and hadronic gamma-ray emission
mechanisms and discuss possible multi wavelength counterparts of the bubbles. In spite
of a lot of progress in the study of the Fermi bubbles, the problem of their origin and
the emission mechanism is still unresolved. It promises to be an interesting and dynamic
research area in the future.