To solve defects that a fork lift requires a fork inserting opening on a battery chamber bottom part of a vehicle body and a battery upper surface, and requires labor for releasing and locking a battery stopper at a time of replacement, a roller for moving a battery and a stopper are necessary on the battery chamber bottom part of the vehicle body for a battery replacing device, and thus it is difficult to fix the battery and great looseness is caused.

A table 5 including a jack 4 is provided on the bottom part 21 of the battery chamber 2 of a vehicle, and the battery 1 is loaded. A side wall height HW of the battery chamber 2 is lowered a little than an ascent limit height HU of a table upper surface 51.