PURPOSE: To enable a car floor to be comfortably used as a tatami by improving ventilation performance of the car floor and preventing moisture.

CONSTITUTION: A car floor tatami preventing device of a home elevator is provided with a ventilating hole provided steel plate 12 attached on a floor framing 6 of the car, and provided with ventilating holes 10, filter clamps to be screwed to the ventilating holes 10 of the ventilating hole provided steel plate 12, and filters 11 attached on the bottom surfaces of the filter clamps. And an incombustible tatami 9 is spread all over at the same height as a car sill 2. Moreover, in the filter clamps, parts so grooved as to be screwed to spiral grooves of the ventilating holes 10 are formed so as to have the diameter approximately equal to that of the ventilating holes 10, and the bottom surfaces to which the filters are attached are so formed as to have the diameter larger than that of the ventilating holes 10. Accordingly, outside air is allowed to flow from the ventilating holes 10 of the ventilating hole provided steel plate 12 while a cage travels in a hoistway, and wind passes through the incombustible tatami 9.