PURPOSE: To reduce errors of decision and to automate by a simple device by providing different identifications at respective connection sets, connecting components to corresponding sets, and identifying an identification mark not covered with the component, thereby reversely identifying a terminal connected to the component.

CONSTITUTION: A position in a board of a component connecting part for setting a code value of a printed board 4a in which a component is mounted is decided in response to the board 4a. The board 4a is so moved that the part falls within a reading range of a bar code reader 5a. The reader 5a reads a bar code 3a. In this case, since the code 3a corresponding to the set of a terminal connected with the component 2a is covered with the connected component 2a, it cannot be identified, and all the code 3a not covered are read. The information is sent to a bar code analyzer 6a. The analyzer 6a analyzes the signal, reversely identifies the set of the terminal connected to the component 2a, and identifies the corresponding type.