An induction heating device and an induction heating method are provided. The entire areas to be heated of the workpiece can be uniformly heated to a predetermined high temperature, and uniform heating is possible even when the workpiece deforms in a non-uniform manner during heating. When areas to be heated are established on a workpiece so as to extend in one direction and the areas to be heated are induction-heated, the deformation amount on one edge of the areas to be heated is different from that on the other. This induction heating device includes; heating coils facing a portion of the areas to be heated when the workpiece is induction-heated; and a relative transfer means for transferring the workpiece and the heating coils along one direction in a relative manner, and the heating coils are disposed so as to correspond to the areas to be heated during the heating period.