To provide a method adapted for performing an electrical test of each of the wiring board regions, i.e., the electrical-component mounting device, while sustaining the state of the collective board, in the method of fabricating an electronic-component mounting device through the use of a collective board having a plurality of wiring board regions electronically connected with one another with plated wires.

A dicing tape 38 is applied onto the back-surface 32b of the collective board 32. Such notches are formed as to allow cutting the plated wire 36 in the sections between the wiring board regions 34 of the collective board 32 to isolate electrically each wiring board region 34. The dicing tape 38 is peeled off. A test terminal 40 is brought into contact with a terminal on the back-surface side to perform an electrical test of the wiring board region 34.