To provide an automatic raising/lowering control method for a mobile generator and an automatic raising/lowing frame control device for automatically adjusting in the horizontal direction without causing distortion and twist to be a cause of a failure and malfunction of the device in automatic raising operation and automatic lowering operation of the mobile generator.

The automatic raising/lowering frame control device for mobile generator is structured of a mobile generator B for performing a demand purpose in a demand place, virtual outer cases 3a and 3b for outrigger projected and pulled in the horizontal direction from both sides of both ends of a chassis integrally formed or loaded with the mobile generator B and having a build-in jack 4, virtual inner cases 4a and 4b inserted into the virtual outer cases 3a and 3b and appearing/disappearing in the vertical direction, an inclination correcting angle sensor 6 for detecting inclination of the mobile generator B forward, backward, right and left, a distributor 7 for reflecting a detection value of the angle sensor 6 to the jack 4, and a remote radio control operating device to be wirelessly operated from outside.