A movable floor device for a vehicle, which comprises a movable board disposed beneath feet of an occupant seated in an occupant seat, a drive source disposed below the occupant seat, and a driving-force transmission mechanism adapted, according to a driving force of the drive source, to input a force directed in a selected one of frontward and rearward directions of a vehicle body, into a rear portion of the movable board. The movable board is supported in such a manner as to be selectively displaced upwardly and downwardly in response to respective ones of the frontward and rearward forces input from the driving-force transmission mechanism. The movable floor apparatus of the present invention makes it possible to allow a lowermost height position of a movable board to be set at a lower level so as to cope with various seating postures with enhanced flexibility.