Let $H_1$ ($Delta$, M) be the family of all 1-1 holomorphic mappings of the unit disk $Delta; subset; C$ into a complex manifold M. Following the method of Royden, Hahn introduces a new pseudo-differential metric $S_{M}$ on M. The present paper is to study the product property of the metric $S_{M}$ when M is given by the product of two domains $D_1$ and $D_2$ in the complex plane C, thus investigating the hyperbolicity of the product domain $D_1 ; imes; D_2$ with respect to $S_{M}$ metric.