  We report the detection of extended emission around the anomalous X-ray
pulsar AXP 1E1547.0-5408 using archival data of the Chandra X-ray satellite.
The extended emission consists of an inner part, with an extent of 45arsec and
an outer part with an outer radius of 2.9arcmin, which coincides with a
supernova remnant shell previously detected in the radio. We argue that the
extended emission in the inner part is the result of a pulsar wind nebula,
which would be the first detected pulsar wind nebula around a magnetar
candidate. Its ratio of X-ray luminosity to pulsar spin-down power is
comparable to that of other young pulsar wind nebulae, but its X-ray spectrum
is steeper than most pulsar wind nebulae. We discuss the importance of this
source in the context of magnetar evolution.
