  We propose the exact solution of the equation in separated variable which
appears in the process of constructing solutions to the quantum Calogero-Moser
three-particle problem with elliptic two-particle potential $g(g-1)\wp(q)$.
This solution is found for special values of coupling constants $g\in {\mathbb
Z}, \, g>1$. It can be used for solving three-paricle CM problem under
appropriate boundary conditions.
