PURPOSE: To enable the analyzation of defectives without increasing the number of package leads, by a method wherein the outputs of functional circuits in a semiconductor chip are connected to those vacant pieces of pads for semiconductor chip bonding which are not electrically connected to package leads.

CONSTITUTION: A functional circuits 2 receives a group 4 of output and input signals of a functional circuit 1 and emits a group 5 of output signals. Since this circuit uses 20 lines at the sum of I/O signal lines and power source lines, the number of outer leads of the package is 20. The semiconductor chip with a formation of this circuit has the function circuits built in cell arrays 9: the number of necessary pads is 20, and the rest 12 pieces are vacant pads as shown by numerals 8. A group 10 of signal lines for analyzing defectives each branching out of the output signal lines of the functional circuit 1 is drawn out and connected to the vacant pads 8. Said group 10 drawn out has eight lines, whereas the number of the vacant pads is 12; therefore, the vacant pads have rooms remaining. Then, the analyzation whether the function circuit 1 or 2 is defective can be made by utilizing said group 10.