The present invention is a method of assembling a device employing electric ignition by comprising assembling an igniter assembly in the device, the igniter assembly having an electric igniter provided with a first electroconductive pin and a second electroconductive pin, connected to a power source, the method comprising steps of: forming two measurement circuits by using the first electroconductive pin and the second electroconductive pin as a measurement terminal on one end side, respectively, and using another member provided in the igniter assembly as a terminal on the other end side with a pass through a dielectric provided in the igniter assembly, measuring pure resistances and/or impedances of the two measurement circuits, respectively, by applying a high frequency thereto separately, distinguishing the first electroconductive pin from the second electroconductive pin from a magnitude relationship (difference) between the measured pure resistance and/or impedance values, and then, disposing the igniter assembly to the device such that the first electroconductive pin and the second electroconductive pin correspond to predetermined power source electrodes, respectively.