Abstract: The present invention relates to a device for reversibly supporting the seat of a vehicle. When a tractor or like vehicle is used for working with a backhoe or like work machine attached to the rear end of the vehicle, a forward operation seat and a rearward operation seat are conventionally needed and are therefore uneconomical. Furthermore, the work mahcine must be spaced from the vehicle body to avoid interference between the two sheets. This entails the problem of impairing the weight balance longitudinally of the vehicle. To overcome these problems, a support table is mounted on the vehicle body by a parallel link assembly which is pivotally movable longitudinally of the body, and a swivel table for supporting the seat thereon is mounted on the support table swivelably about a vertical shaft. Further provided is a lock for locking the swivel table against swiveling about the shaft, and unlocking device for unfastening the lock.