A magnetic reading head is provided. The magnetic reading head reads information recorded on a recording medium having a soft underlayer and a magnetic layer stacked on the soft underlayer, and includes a magneto-resistive element and a pair of shield layers. The magneto-resistive element is positioned over the magnetic layer, keeping a predetermined distance G from the soft underlayer. The pair of shield layers are arranged parallel to the magneto-resistive element, keeping predetermined distances from both sides of the magneto-resistive element. Here, the shield layers have widths less than double of the predetermined distance G. In this structure, by properly adjusting the widths of the shield layers, magnetic fields formed by the magnetization of the recording medium under the shield layers do not affect the magnetoresistive element. As a result, sensitivity of the magnetic reading head can be improved.