To provide an automatic loading device and an automatic loading method of a panel-like member, capable of loading the panel-like member in a pallet, without using an external power source.

A front end part is advanced by being supported by a hook 21 by engaging the front end of the panel-like member W pushed out of the carrier conveyor 1 front end with the hook 21 arranged in a slider 18, and the panel-like member W itself and the slider 18 are advanced along a guide plate 20 and a free roller conveyor 16 by gravity of the pane-like member W itself in a stage when the rear end of the panel-like member W moves on the guide plate 20 from above a carrier conveyor 1, and the rear end side is lowered on the pallet 3 by leaving the front end supported by the hook 21 in a stage when the rear end of the panel-like member W is separated from the front end of the guide plate 20, and the front end is lowered on the pallet 3 by separating the front end from the hook 21 in a stage when the rear end side lands on the pallet 3.