A multidirectional switch and an operation unit containing the switch, to be used for controlling an automobile air-conditioner, etc. The unit includes a single-hand fire extinguisher and a holder for releasably supporting the fire extinguisher on a vertical surface. Chemical Formula 1 1wherein R1, R2, R3 and R4 are, respectively, groups which may be the same or different and independently represent an aryl group of the following general formula. Finally, the air duct is removed from the mold.