To provide a walking crane capable of indicating use as a foundation work machine on an external indicator, while making the most use of the function as the external indicator.

This walking crane includes a safety device for stopping operation to the danger side by monitoring a work state and the external indicator 18 for turning on any one of three-color light emitters of a red light emitter 22, a yellow light emitter 21 and a green light emitter 20 in response to the work state. The external indicator turns on any two colors of three colors of a red color system, a yellow color system and a green color system when the safety device is released.