PURPOSE: To obtain a method for inspecting a faulty heat seal connector within a heat seal connector original sheet readily and accurately.

CONSTITUTION: In an inspection method of a heat seal connector original sheet 7 where a plurality of heat seal connectors with a plurality of conductive lines 3 are formed on a substrate 2 which consists of an electrically insulated transparent resin, a heat seal connector original sheet is displayed on a display 15 in an original size. After a faulty symbol x is displayed at a corresponding part of the heat seal connector with a disconnection of the conductive lines and a short circuiting between the conductive lines 3 which are detected by a detector 11, the heat seal connector original sheet 7 itself is overlapped on the display screen. After the faulty symbol x is seen through and the faulty heat seal connector on the heat seal connector original sheet 7 is marked, each heat seal connector is separated and then the faulty heat seal connector is eliminated.