PURPOSE: To minimize the size of a service vehicle for work at a high location by positioning a liftably supported service wagon above the roof of an automobile and to prevent exposure of an equipment/instrument, used at the high-location servicing time, to the rain even if the work is done under such rainy weather by housing the equipment/instrument into the automobile.

CONSTITUTION: A service wagon 4 which can be lifted to a specified height by a service wagon lifting machine 3 is installed above the roof 2 of a one-box type light four-wheel atuomobile 1. The body of the automobile has at the rear thereof rear ascending and descending steps 5 by which a workman may ascend to and descend from the service wagon 4. The wagon 4 consists of a lower frame 6, a bottom board 7, pedestals 8 which are installed at the four corners of the frame 6 as able to be turned by approximately 90°, and handrails 9 which run between the pedestrals 8. At the servicing time, the pedestrals 8 are raised upright and the hooks of round bars are engaged with parts of the pedestrals 8 so as to prevent the pedestrals 8 from falling down during the serve.