PURPOSE: To move, fit an detach a mast step through a one action manual operation, by a method wherein a mast step provided with a universal joint at its top part is provided with a liftable shaft, and a rotary engaging part provided at a lower part of the shaft is operated through an engagement with a cam.

CONSTITUTION: The mast step 3 which penetrates vertically through a main body 2 of the sailing board and supports a mast 4 through the universal joint provided at the top part thereof is provided with the shaft 9 capable of being lifted and lowered by an operating end 10. The shaft 9 is constantly energized upwards by a spring 22, and when being moved downwards by depressing the operating end 10, it is rotated by 90° by a groove 16 of the cam 15, operates the rotary engaging part provided at the tip thereof, and releases the engagement between the engaging part and a part 24 to be engaged which is provided at a lower part of the main body 2. Accordingly, the mast step is moved and detached in the manner of a one action manual operation. When fitting the mast step, the operating end 10 is further depressed.