  We determine explicitly the foliated cohomology $H_{\cal F}^\ast (M)$ of the
affine Reeb flow ${\cal F}$ on the Hopf manifold ${\Bbb S}^n\times {\Bbb S}^1$.
The vector space $H_{\cal F}^1(M)$ contains exactly the obstructions to solve
the cohomological equation $X\cdot f=g$ where $f$ and $g$ are $C^\infty
$-functions and $X$ is any non singular vector field defining the foliation
${\cal F}$. The topological dual of $H_{\cal F}^1(M)$ is the space of
distributions invariant by $X$.
