The present invention relates to a mobile substation comprising a chassis on which substation equipment are carried, king pins which are respectively fixed at both end parts of the chassis, a tractor which includes a coupler adapted to detachably couple to either of the king pins and which supports one of the end parts of the chassis, a bogie truck which includes a coupler adapted to detachably couple to the other king pin and which supports the other end part of the chassis, and supporting legs which are respectively disposed at both the end parts of the chassis and which support the chassis when the chassis is being attached to and detached from the couplers of the tractor and the truck.
