A mounting system which mounts an LED element on a board and mounts a lens so as to cover the LED element, in which control devices which control operations of operating machines include an LED element mounting unit which mounts the LED element in a predetermined mounting position, a deviation amount acquisition unit which acquires a deviation amount between a mounting position and the predetermined mounting position of the LED element, a first lens mounting unit which mounts the lens on the board using a position of the LED element mounted on the board as a reference, when the deviation amount is smaller than a threshold value, and a second lens mounting unit which mounts the lens in a preset position on the board, regardless of the position of the LED element mounted on the board, when the deviation amount is equal to or greater than the threshold value.