To estimate the forward rate of a device with high accuracy and to enable the device to be used for rolling control by setting a criterion for detecting the strip admission/strip extraction of a material to be rolled based on a value executing averaging processing and regression processing to the actual results of rolling at each rolling stand.

The admission/extraction of a sheet at each of rolling stands 11, 12 are detected with a sheet presence signal generating circuit 14 and a sheet presence signal is generated. The moving speed of a material 13 to be rolled between the rolling stands is determined by a speed calculating means (a roll feeding length calculating circuit 15 or the like). A forward rate is determined based on the moving speed of the material 13 to be rolled with a forward rate calculating circuit 16 provided on a forward rate estimating device. A criterion for detecting the strip admission/strip extraction of the material 13 to be rolled at the rolling stands is set based on a value executing the regression process or the averaging process to the actual result value of rolling at each of the rolling stands 11, 12 with the sheet presence signal generating circuit 14.