PURPOSE: To control the transportation of flammable fluid and the transportation of fluid in the flammable gas atmosphere and enhance operation efficiency of the system, by utilizing optical signals and controlling driving of a pump, a motor and the like to deliver fluid from a remote site.

CONSTITUTION: A light emitting module 24 consists of LED or LD, an electric- optical exchange element, and an electric circuit to allow said element to emit light. A photo detective module 25 consists of PD or APD, an optical-electric transfer element, and an electric circuit such as signal amplifying or the like. Accordingly, light emitting from the light emitting module 24 returns to the photo detective module 25 through an optical fiber without being stopped by a nozzle section 10, allows the electric current to flow to an electric coil of a relay in an electromagnetic on-off device 23 of a motor 22 driving a pump 21 to feed the fluid to the nozzle section 10. Said operation is carried out by cutting the light by means of a handle 13 of the nozzle section 10 is hand.