  We present the ASCA and Suzaku studies of the TeV source HESS J1837--069,
which has not been identified in other wave-lengths. We confirm the presence of
two X-ray sources in the Suzaku XIS image, AX J1838.0--0655 and AX
J1837.3--0652, near both ends of the elongated TeV emission region. The XIS
spectra of the two sources are reproduced by an absorbed power-law model, whose
parameters are all consistent with those determined by the ASCA data. Recently,
70.5 ms X-ray pulsation has been detected with RXTE in the sky region including
HESS J1837--069 (2008, ApJ, 681, 515). Using the ASCA GIS data which has both
timing and imaging capabilities, we identified the pulsation source as AX
J1838.0--0655. The pulse periods determined by ASCA and Suzaku, and that
reported with RXTE indicate steady spin-down at $\dot{P} = 4.917(4) \times
10^{-14}$ s s$^{-1}$. These results suggest that AX J1838.0--0655 is an
intrinsically stable source, and presumably a pulsar wind nebula (PWN). We
discuss the possibility that AX J1838.0--0655 is associated with HESS
J1837--069 and the VHE gamma-ray emission is originated from the PWN.
