The reverse squeezing low of dilute polymer solutions has been studied utilizing a flat plate and a spherical surface of a large radius of curvature. In this experiment, both surfaces are forced to separate by applying constant forces from a stationary and contacting state. All the liquids used are Newtonian in viscosity. The following points are found by comparing the results of inelastic liquids and viscoelastic liquid. In the case of the viscoelastic liquid, the surfaces separate from each other much more slowly than in the case of the inelastic liquid. This trend is clearly shown when the separation is small. The results predicted by the theory of inelastic fluids with the assumption of the quasi-steady state agree well with the experimental results. The same assumption, however, cannot explain the slow separation effect because of a small contribution of elastic terms.