  In his famous monographs, Einar Tandberg-Hanssen writes that "the single,
physically most important parameter to study in prominences may be the magnetic
field. Shapes, motions, and in fact the very existence of prominences depend on
the nature of the magnetic field threading the prominence plasma". Hereafter we
sumarize recent contributions and advances in our knowledge about the magnetic
field of solar prominences. It mostly relies on high resolution and high
sensitivity spectropolarimetry made both in the visible and in the near
infrared.
