  We present here two epochs of Space VLBI Observations at 18 cm of the BL-Lac
type object MKN 501. Thanks to the high resolution of these new data, we have
found that the inner jet is centrally brightened at its beginning, but becomes
extended and limb brightened at ~8 mas from the core. Moreover a comparison
between the two epochs shows the presence of a proper motion with apparent
velocity = 6.7c. Observational data have been used to constrain the jet
velocity and orientation.
