Аннотация:The properties of interface (Tamm) minibands in a superlattice are investigated in the framework of simple exactly soluble model. In case of nondegenerate bands of constituent slabs of superlattice a couple of Tamm minibands arises from localized at the neighboring interfaces Tamm states. It is shown that envelope function approximation describes these minibands very precisely, if the distinctions between band edge Bloch functions of adjacent slabs are taken into account in the boundary conditions. The case of inverted bands is the only exception: in that case Tamm states and minibands are not sensitive to the boundary conditions.