To overcome a problem such that upsizing of a device, an increase in weight and the like are caused by securement of rigidity because a concentrated load acts on an end of a link arm of the conventional device.

A wheelchair elevating device is equipped with: paired slide rails which are arranged on a vehicle body floor in parallel in the direction of an opening of a vehicle body; a carriage which is provided slidably on both the slide rails, and slide-driven in a lengthwise direction by a driving mechanism; paired support members 5 and 6 which are provided in the carriage in a vertically slidable state, and driven for ascent/descent by an elevating mechanism; and an elevating plate 7 which is provided between the support members 5 and 6, and allows a wheelchair to be placed and supported on a top surface. The wheelchair on the elevating plate 7 is horizontally moved by the carriage and vertically moved by both the support members 5 and 6, and the whole of a moving locus is made to ascend/descend by a rectilinear motion, so that the occurrence of the concentrated load can be prevented.