The invention relates to outdoor lighting devices used mainly in emergency situations. The inventive light tower comprises an inflatable mast, including a flexible transparent shell, fixed to a support flange provided with an air intake vent for pumping compressed air into a shell chamber, an electric lamp fixed in the shell, an air pump driven with a motor, a working chamber connected to the vent, and power supply means substantially connected to the lamp and in some embodiments to the pump. The shell is divided into a lower and upper parts joined with an airtight coupling means. The mast is furnished with means for changing the length associated with the upper part. A control unit for the light tower and power means are mounted on the flange. The air supply into the shell chamber is manually/automatically adjustable. In several embodiments light reflectors and inflate modes are described.