PURPOSE: To manufacture a good electrical steel plate which is excellent in machinability and excellent in magnetic properties in a medium magnetic field by executing dehydrogenation heat treatment as necessary and successively executing annealing or normalization after hot rolling to a low carbon steel billet of a specific composition under specified conditions.

CONSTITUTION: The low carbon steel billet of the composition contg., by wt.%, <0.01% C, 0.10-3.50% Si, <0.20% Mn, 0.02-0.20% S, <0.040% Al, <0.004 % N, <0.005 % O, <0.0002% H is heated to 950-1150°C and, after executing rolling in which one or more times of rolling passes of rolling shape ratio A expressed by an equation I is ≥0.6 at ≥800°C is executed, rolling whose draft at ≤800°C is taken as 35-70% is executed. As for a thick steel plate of ≥50mm thickness, as necessary, after executing dehydrogenation heat treatment at 600 750°C, annealing at 750-950°C or normalization at 910 1000°C is executed. As for a steel plate of <50mm thickness, by executing the above-mentioned annealing or normalization, the good thick electrical steel plate excellent in machinability and excellent in magnetic properties in the medium magnetic field are manufactured.