To provide a material to be carried loading device of simple and low-cost structure capable of automatically loading a heavy material to be carried on a deck of a truck in a short time even if the material to be carried is heavy.

This device 1 is provided with a support stand 7, a support stand lifting means (cross-link mechanism 10) for lifting the support stand, a pallet supporting means (roller conveyor 8) supported by the support stand freely to move in the horizontal direction to support the pallet freely to move in the horizontal direction, a pallet moving means (driving motor 19) for moving the pallet supported by the pallet supporting means in the horizontal direction, a displacing means (driving cylinder 22) for displacing the pallet supporting means supported by the support stand in the horizontal direction, and a deck side height adjusting means (driving cylinder 28) provided in front of the pallet supporting means to hold the pallet supporting means at the predetermined height level in relation to the deck of the truck and to lower the pallet supporting means by releasing the holding.