A thin-film magnetic head which suppresses the TPTP phenomenon due to the environment temperature is provided. The thin-film magnetic head includes, an electromagnetic coil element having a coil layer and coil-insulating layer, and an overcoat layer. A width of the coil-insulating layer in a track-width direction is larger than a width that is needed to insulate the whole coil layer, and is at least 46 μm, and a length of the coil-insulating layer in a direction perpendicular to the track-width direction is larger than a length that is needed to insulate the whole coil layer, and is at least 75 μm. In addition, a heat expansion coefficient of the coil-insulating layer is larger than or equal to 30×10−6/K, and a Young's modulus of the coil-insulating layer is larger than or equal to 1 GPa and smaller than or equal to 4 GPa.