PURPOSE: To strengthen structure as well as to maintain safety of a driving-in floor of a pit upper stage in a pit type multistory parking device.

CONSTITUTION: Vertical frames 2 are erected on four corners of a space arranging on-vehicle pallets in a lateral row, and by connecting longitudinal and lateral frames 4, 5 to their upper ends, a frame body is constituted. In this frame body, a driving-in floor provided with a traverse pallet 16 free to move in the sideway direction and a ground floor provided with an elevating pallet free to move vertically are arranged. Between each of the elevating pallets 15, 15, vertical frames 3 are erected longitudinally, a beam 22 is provided between the vertical frames 3, 3, a collar 18 roughly in the width of the vertical frame 3 is projectively provided on one of edges of the traverse pallet 16, and a projection 19 roughly in the width of the vertical frame 3 is provided on the other of the edges of the traverse pallet 16. The neighbouring traverse pallets 16 eliminate a clearance as the collar 18 and the projection 19 are overlapped.