To realize manufacture of a product which is compressed to its center part at high productivity and low cost as compared with forging and, moreover, to combine the advantage of rolling and improvement of quality of steel by forging.

A long size continuously cast material 20 having forgeable steel property, an approximately square cross section and sloped corner regions are used as raw materials. By forming this continuously cast material 20, by heat for forging not lower than transition temp. and with at least one 2-roll stand 2, 3 and at least one 4-roll stand 5, 7, alternately continuously and so as not to generate twist and, moreover, by comparably slightly elongating a rolled stock, the cast material is subjected to forming process of multiple stages by comparatively very high rolling force and the rolled stock which is compressed to the center part is manufactured.