  The Weyl-Wigner-Moyal formalism for quantum particle with discrete internal
degrees of freedom is developed. A one to one correspondence between operators
in the Hilbert space $L^{2}(\mathbb{R}^{3})\otimes{\mathcal{H}}^{(s+1)}$ and
functions on the phase space $\mathbb{R}^{3}\times\mathbb{R}^{3}\times
\{0,...,s\} \times\{0,...,s\}$ is found. The expressions for the
Stratonovich-Weyl quantizer, star product and Wigner functions of such systems
for arbitrary values of spin are obtained in detail. As examples the Landau
levels and the corresponding Wigner functions for a spin $\frac{1}{2}$
nonrelativistic particle as well as the magnetic resonance for a spin
$\frac{1}{2}$ nonrelativistic uncharged particle are analysed.
