To provide, with regard to a floor construction method used for a building such as a general house, a construction method for a vibration-proof floating floor which can suppress oscillation from an upper floor to a lower floor of the house.

The construction method for a vibration-proof floating floor is composed in such a way that a board 9 processed with a special shiplap work is laid over a floor substrate material 8 and a stick 10 processed with a special shiplap work is inserted into the joint. This enables the stick 10 to float in the air. Accordingly, the stick 10, by floating in the air, does not contact the floor substrate material 8 directly, so as to prevent transmission of the oscillation of the upper part to the lower part.