The present invention provides a sheet thickness control system, which can ahs good response and perform high-precision sheet thickness control when the feeding speed of the pressed material is low. A control section (10) has a feed-forward correction amount calculation section (14), which calculates the feed-forward correction amount corresponding to the roller speed (VR) of a rolling machine (4). The control section (10) uses the feed-forward correction amount calculated by the feed-forward correction amount calculation section (14) to correct the mass flow sheet thickness estimated by detecting values based on an inlet sheet thickness meter (7e), an outlet sheet thickness meter (8d), as well as an outlet sheet speedometer (8e), to estimate the mass flow sheet thickness (h[MF]). Mass flow sheet thickness control section (17) perform the sheet thickness control to the rolling machine (4), based on the mass flow sheet thickness (h[MF]) corrected by the feed-forward correction amount.