To facilitate attaching by a fixing method to match suspension standards, and to easily connect an FPC to a head amplifier by shortening a distance between a head amplifier substrate and a magnetic head to reduce noise.

In a disk characteristic evaluating device 1, a suspension 49 having a magnetic head 23 provided in its tip is freely attached to/detached from a head clamp 73. The head clamp 73 positions the magnetic head 23 on a magnetic disk 9. A projected part is provided in the bottom surface of the suspension 73, and a positioning hole for positioning the outer diameter of the projected part is provided in the head clamp 73. A clamping member slidable from a rear side is provided so as to press the upper surface of the suspension 49 fixed in the positioning hole. A head clamp substrate is incorporated in a head clamp main body. An FPC connector is provided in the head amplifier substrate to directly clamp and connect the FPC end of the magnetic head 23 to the contact of the head amplifier substrate.