A method of manufacturing a flying magnetic head of composite type using a magnetic thin film layer as a head core. The flying magnetic head comprises a slider, an I core bar bonded via a high-melting-point bonding glass layer to one end face of the slider and a C core bonded via a high-melting-point bonding glass layer serving as a gap spacer to the I core bar. The I core bar and C core have respective magnetic thin film layers, which are aligned to each other and mated with an ABS of the slider. I core bar is formed at a position corresponding to a wiring groove of the C core with a window groove. Such flying magnetic heads having a smooth ABS can be readily and massively manufactured.