In an opto-magnetic disk type writing/reading apparatus having a magnetic head held by a suspension load beam in an air-borne floating state over a surface of the opto-magnetic disk, the suspension load beam is raised up or put down in a manner that firstly the opto-magnetic disk is revolved at a higher revolution speed than the predetermined rated revolution speed for a predetermined short period, and thereafter the revolution speed is lowered to the predetermined revolution speed after soft-landing putting down of the magnetic head to achieve a steady-state air-borne floating position.