It is possible to provide a display panel substrate capable of preventing dielectric breakdown of an insulating film, a display panel using the substrate, a display panel substrate manufacturing method or a display panel manufacturing method. An inspection wire (123) which transmits a signal for inspection includes a first part (1231) having a portion superimposed on and/or intersecting an input wire (121) pulled from a data signal line of a display region (111) and a part (1232) not having the portion which sandwich a first insulating film (141). These parts are shaped by electrically separate bodies and electrically connected by a conductor (128), so as to minimize the area difference between the first part (1231) superimposed on and/or intersecting the input wire (121) pulled from the data signal line and the input wire (121).