To provide a means free from wiring trouble and machining that requires much time and labor regarding a technique for transmitting measured data testing environment in a weather resistance testing tank at real time from a rotating sample frame to the outside of the testing tank.

This weather resistance light testing device with an artificial light source disposed in the testing tank and with each sensor for temperature, humidity and light energy placed on the sample frame rotating around the artificial light source, is provided with a touch panel outside the testing tank, capable of continuously recording the change of temperature detected by a temperature sensor characterized by mounting an R-element of a CR oscillating circuit instead of a potentiometer interlocked with a spiral bimetal shaft of a thermally sensitive part of the temperature sensor as a representative example. The above temperature sensor is incorporated in a sample holder and mounted on the sample frame, and a transmission unit is mounted to the sample holder to constitute the weather resistance light testing device provided with the temperature sensor permitting the total elimination of a mechanical rotating mechanism and electrical noise.