  It is solved a problem of construction of separately continuous functions on
the product of compacts with a given discontinuity points set. We obtaine the
following results.
  1. For arbitrary \v{C}ech complete spaces $X$, $Y$ and a separable compact
perfect projectively nowhere dense zero set $E\subseteq X\times Y$ there exists
a separately continuous function $f:X\times Y\to\mathbb R$ the discontinuity
points set of which equals to $E$.
  2. For arbitrary \v{C}ech complete spaces $X$, $Y$ and nowhere dense zero
sets $A\subseteq X$ and $B\subseteq Y$ there exists a separately continuous
function $f:X\times Y\to\mathbb R$ such that the projections of the
discontinuity points set of $f$ coincide with $A$ and $B$ respectively.
  An example of Eberlein compacts $X$, $Y$ and nowhere dense zero sets
$A\subseteq X$ and $B\subseteq Y$ such that the discontinuity points set of
every separately continuous function $f:X\times Y\to\mathbb R$ does not
coincide with $A\times B$, and $CH$-example of separable Valdivia compacts $X$,
$Y$ and separable nowhere dense zero sets $A\subseteq X$ and $B\subseteq Y$
such that the discontinuity points set of every separately continuous function
$f:X\times Y\to\mathbb R$ does not coincide with $A\times B$ are constructed.
