PURPOSE: To always confirm not only coating defects but also the state during the coating with a fluid by outputting an electromagnetic wave to the tip of a nozzle while applying the fluid by the nozzle and displaying the coating state of the fluid stepwise or analogously on the basis of the receiving quantity of the electromagnetic wave received at a coating rear stage position.

CONSTITUTION: When an electromagnetic wave is outputted to a nozzle 3 from a control unit 9 and an adhesive G is applied from the nozzle 3, the electromagnetic wave is received by a receiving part 4 through the adhesive G. Therefore, the nozzle 3 functions as an electromagnetic wave transmission part 5. The receiving part 4 is integrally fixed to a nozzle main body 1 by a ring-shaped fixing member and the detection signal of the electromagnetic wave detected by the receiving part 4 is supplied to the control unit 9 but, since it is changed by the coating amt. of the adhesive G, the coating amt. of the adhesive can be easily detected electrically. The detection signal is stepwise displayed on a level display part 7 by arranging a plurality of LEDs so as to be capable visually confirming the coating amt. of the adhesive G corresponding to the detection quantity of the electromagnetic wave.