Abstract: A method for setting a safe work area and a rated load in a swing type work machine, as well as a swing type work machine which utilizes the said method, are disclosed. An area where a strength-based safe work area which is established taking the strength of a swing member into account and a stability-based safe work area which is established taking the stability of the work machine into account overlap each other, is set as a safe work area to be used actually. Likewise, out of a strength-based rated load which is set taking the strength of the swing member into consideration and a stability-based rated load which is set taking the stability of the work machine into consideration, the lower one is set as a rated load to be used actually. Using the safe work area and rated load thus obtained, there are made a safety control and an appropriate display.