To improve operability in remote wireless-operating a hydraulic excavator while watching an image transmitted from hydraulic excavator side to operator side.

A plurality of actuators are remote-radio-controlled based on images on a television monitor 10 by digitizing an image signal outputted from a television camera 1 which is loaded on a hydraulic excavator by an image processor 2 for compression, and transmitting it to operator side. The image processing device 2 is formed with an image compressor 18a for low speed which has image processing speed meeting an actuator which produces a slow image change, and an image compressor 18b for high speed which has image processing speed meeting an actuator which generates quick image change. The image compressors 18a, 18b are connected to an image compression switch 19, and when the actuator which produces a quick image change is operated, the image compression switch 19 detects its operating signal and automatically selects the image compressor 18b for high speed.