PURPOSE: To manufacture a thin-film magnetic head with a high yield, which excels in the distribution of thickness by cutting a base board by grinding after head element is formed on the base board of the thickness of not less than a specific value.

CONSTITUTION: A lower part magnetic layer 3, a gap layer 5, a coil conductor layer 9, an upper part magnetic layer 11 and the like are laminated to form a head element on a block base board of not less than 5.2mm thick. After that, grind cutting is performed to manufacture a thin-film head 20. When the diameter of the base board is 3 inch and the thickness is not less than 5.2mm and each insulating layer is made up of SiO2, an amount of warp of the base board becomes not more than 0.3μm, and the accuracy of thickness required for the design of a thin-film head can be obtained. Therefore, thickness of each layer making a magnetic core and a coil can be uniformly formed with high accuracy.