  We report the results of Suzaku observations of the young supernova remnant,
Vela Jr.\ (RX J0852.0$-$4622), which is known to emit synchrotron X-rays, as
well as TeV gamma-rays. Utilizing 39 Suzaku mapping observation data from Vela
Jr., a significant hard X-ray emission is detected with the hard X-ray detector
(HXD) from the north-west TeV-emitting region. The X-ray spectrum is well
reproduced by a single power-law model with the photon index of
3.15$^{+1.18}_{-1.14}$ in the 12--22 keV band. Compiling this with the soft
X-ray spectrum simultaneously observed with the X-ray imaging spectrometer
(XIS) onboard Suzaku, we find that the wide-band X-ray spectrum in the 2--22
keV band is reproduced with a single power-law or concave broken power-law
model, which are statistically consistent with each other. Whichever the model
of a single or broken power-law is appropriate, clearly the spectrum has no
rolloff structure. Applying this result to the method introduced in
\citet{yama2014}, we find that one-zone synchrotron model with electron
spectrum having a power-law plus exponential cutoff may not be applicable to
Vela Jr.
