  We present the analysis of archival data from ROSAT and ASCA of a
serendipitous BL Lac object PKS 2316-423. Because of its featureless
non-thermal radio/optical continuum, PKS 2316-423 has been called as a BL Lac
candidate in the literature. PKS 2316-423 was evidently variable over the
multiple X-ray observations, in particular, a variable high-energy tail of the
synchrotron radiation is revealed. The X-ray spectral analysis provides further
evidence of the synchrotron nature of its broad-band spectrum: a steep and
downward curving spectrum between 0.1--10 keV, typical of high-energy peaked BL
Lacs (HBL). The spectral energy distribution (SED) through radio-to-X-ray
yields the synchrotron radiation peak at frequency Vp=7.3 10^{15} Hz, with
integrated luminosity of Lsyn=2.1 10^{44} ergs s^{-1}. The averaged SED
properties of PKS 2316-423 are very similar to those ``intermediate'' BL Lac
objects (IBL) found recently in several deep surveys, such as Deep X-ray Radio
Blazar, Radio-Emitting X-ray, and ROSAT-Green Bank surveys. We suggest that PKS
2316-423 is an IBL though it also shows some general features of a HBL.
Actually, this double attribute of PKS 2316-423 provides a good test of the
prediction that an IBL object can show either synchrotron or inverse-Compton
characteristics in different variability states.
