In a die mounting system in which a die supply device is set on a component mounter and dies supplied from a die supply device are mounted on a circuit board by a mounting head of the component mounter, the position of a die is recognized by processing an image of the die on a dicing sheet captured by a camera, a supply head is moved to a die pickup position by a supply head moving mechanism, the die is picked up, the supply head is vertically inverted and moved to a die transfer position, and the die held by the supply head is picked up by a mounting head of the component mounter at a component transfer position and mounted on the circuit board. The die transfer position is set at a position such that die transfer and die imaging are able to be performed in parallel.