[Object] To produce an H-shaped steel product with a flange width larger than a conventional flange width by, in a rough rolling step using calibers in producing H-shaped steel, creating deep splits on end surfaces of a material (e.g., slab) using projections with acute-angle tip shapes, and sequentially bending flange portions formed by the splits.[Solution] Provided is a method for producing H-shaped steel using a slab as a material. In a rolling mill that performs a rough rolling step, a plurality of calibers to shape a material to be rolled, and a web thinning caliber to thin a web of the material to be rolled that has been shaped in the plurality of calibers are engraved, the number of the plurality of calibers being three or more. Shaping of a plurality of passes is performed on the material to be rolled in part or all of the plurality of calibers. In a first caliber and a second caliber among the plurality of calibers, projections to create splits vertically with respect to a width direction of the material to be rolled are formed. In a third caliber and subsequent calibers among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed. The projections formed in the first caliber and the second caliber have a tip angle of 40° or less.