In this paper we show that an algebra Ω(m,n) is functionally free for the Berman class K_<m,n> of Ockham algebras, that is, for any two polynomials f and g, they are identically equal in K_<m,n> if and only if f = g holds in Ω(m,n). This result can be applied to the well-known algebras, e.g.,Boolean, de Morgan, Kleene, Stone, Bunge algebras, and so on.