A magnetic head and a manufacturing method thereof which can suppress side fringing and permeation of a recording magnetic field in the first direction while maintaining the intensity of a recording magnetic field. By making a length of a trailing upper surface of a front portion in a height direction longer than a length of a leading lower surface of the front portion in the height direction, a generated magnetic field of the trailing upper surface can be comparatively weakened, to suppress side fringing and magnetic field permeation of a recording magnetic field. The recording magnetic field can be kept large enough by shortening the length of the leading lower surface in the height direction to intensify a generated magnetic field generated from the leading side.