  Terzan 5, a globular cluster (GC) prominent in mass and population of compact
objects, is searched for diffuse X-ray emission, as proposed by several models.
We analyzed the data of an archival Chandra observation of Terzan 5 to search
for extended diffuse X-ray emission outside the half-mass radius of the GC. We
removed detected point sources from the data to extract spectra from diffuse
regions around Terzan 5. The Galactic background emission was modeled by a
2-temperature thermal component, which is typical for Galactic diffuse
emission.
  We detected significant diffuse excess emission above the particle background
level from the whole field-of-view. The surface brightness appears to be peaked
at the GC center and decreases smoothly outwards. After the subtraction of
particle and Galactic background, the excess spectrum of the diffuse emission
between the half-mass radius and 3' can be described by a power-law model with
photon index $\Gamma$ = 0.9$\pm$0.5 and a surface flux of F$_X$ =
(1.17$\pm$0.16) 10$^{-7}$ erg s$^{-1}$ cm$^{-2}$ sr$^{-1}$ in the 1--7 keV
band. We estimated the contribution from unresolved point sources to the
observed excess to be negligible. The observations suggest that a purely
thermal origin of the emission is less likely than a non-thermal scenario.
However, from simple modeling we cannot identify a clearly preferred scenario.
