The invention discloses an automatic feeder comprising a guide rail, a chain, a toggle sheet and a backstop block, wherein chain width direction locking and length forwarding direction can slide and wind on the outer side surface of the guide rail; the toggle sheet can be expanded along the chain width direction and can be positioned on the guide rail in a sliding mode along the chain length forwarding direction; the backstop block can be expanded along the chain width direction and can be positioned on the guide rail along the chain length forwarding direction; one end of the toggle sheet and one end of the backstop block, which approach to the chain, are respectively contained in two connecting gaps of the chain; one end of the toggle sheet and one end of the backstop block, which approach to the chain, are in rigid backstop with the inner wall of the side of the chain connecting gap along one side of the chain forwarding direction; and one end of the toggle sheet and one end of thebackstop block, which approach to the chain, are in elastic sliding backstop with the inner wall of the side of the chain connecting gap along the other side of the chain forwarding direction. The invention can conveniently and orderly transmit products by causing the chain to carry out intermittent unidirectional movement, which is convenient for products to tap and transmit. Thus the invention can effectively improve production efficiency and is safe to use.