  We investigated the anisotropic magnetic properties of CePd$_2$As$_2$ by
magnetic, thermal and electrical transport studies. X-ray diffraction confirmed
the tetragonal ThCr$_2$Si$_2$-type structure and the high-quality of the single
crystals. Magnetisation and magnetic susceptibility data taken along the
different crystallographic directions evidence a huge crystalline electric
field (CEF) induced Ising-type magneto-crystalline anisotropy with a large
$c$-axis moment and a small in-plane moment at low temperature. A detailed CEF
analysis based on the magnetic susceptibility data indicates an almost pure
$\langle\pm5/2 \rvert$ CEF ground-state doublet with the dominantly
$\langle\pm3/2 \rvert$ and the $\langle\pm1/2 \rvert$ doublets at 290 K and 330
K, respectively. At low temperature, we observe a uniaxial antiferromagnetic
(AFM) transition at $T_N=14.7$ K with the crystallographic $c$-direction being
the magnetic easy-axis. The magnetic entropy gain up to $T_N$ reaches almost
$R\ln2$ indicating localised $4f$-electron magnetism without significant
Kondo-type interactions. Below $T_N$, the application of a magnetic field along
the $c$-axis induces a metamagnetic transition from the AFM to a
field-polarised phase at $\mu_0H_{c0}=0.95$ T, exhibiting a text-book example
of a spin-flip transition as anticipated for an Ising-type AFM.
