A method for bending a work of a plate shape by moving a die with the work being butted against a butting member, and an apparatus for executing the method are provided. The bending apparatus is provided with an input unit for inputting data on bending conditions including respective target values of a bending angle and a bending dimension, as well as respective measured values of a bending angle and a bending dimension of the work obtained in trial bending. A control device installed in the apparatus executes an initial computation for computing an operation amount of the die when the data on bending conditions are inputted. Further, the control device executes computation for a correction value for an operation amount of the die and computation for an estimated value of a bending dimension when the respective measured values of the bending angle and the bending dimension obtained in trial bending are inputted. This way, the control device controls a reciprocating mechanism to correct the position of the butting member according to the estimated value of a bending dimension, and to move the die according to the corrected operation amount.