To provide a method for manufacturing a thick steel plate, which can control a surface hardness of the plate.

The method for manufacturing the thick steel plate having the surface hardness of which the upper limit is specified includes cooling a hot-rolled plate, measuring the surface hardness of the plate, and heating the plate with the use of an induction heating device. The condition of the heat treatment with the use of the induction heating device is selected so that a desired surface hardness can be obtained, on the basis of the relation among the surface hardness of the thick steel plate that has been cooled, a condition of the heat treatment with the use of the induction heating device, and the surface hardness that is obtained after the heat treatment. The above relation is a relation between a difference between the surface hardness of the thick steel plate that has been cooled and the surface hardness obtained after the heating treatment and the surface temperature elevated by the induction heating device; and more preferably is a relation which has been corrected with a measured value obtained when the material is manufactured.