System to load and unload on data area for increase of the storage capacity is on the way to development. On the other hand, small "femto slider" instead of pico slider has been applied to reduce cost. So it is important to investigated load/unload behavior of femto slider for the development of the system. We measured the load/unload behavior of femto slider by laser doppler vibrometer and compared it with that of pico slider. The evaluation results showed that there was neither slider/dimple separation while unloading femto slider nor pitch vibration after unloading because of small residual negative force. However, even femto slider vibrated due to increase of residual negative force in case Z-height is smaller than nominal.