A magnetic head slider supporting apparatus comprises: a suspension flexibly supporting a slider; and a flexible wiring board. The suspension incorporates a load beam. The flexible wiring board is disposed along the load beam. The flexible wiring board includes: first and second lines for connecting a write element that the slider includes to a read/write processing circuit; and third and fourth lines for connecting a read element that the slider includes to the read/write processing circuit. The flexible wiring board further includes two conductors for generating two parasitic capacitances for reducing potential differences created between the third and fourth lines due to write signals transmitted through the first and second lines.