To provide a toy vehicle including a first form/second form in the obverse side/reverse side, and to provide a transforming device and a transforming method for mechanical transformation between the respective forms.

A second arm 50 that is inserted inside the toy vehicle 80 mounted on a first mounting position 30 is moved upward to turn turnably connected members 82a, 82b, 82c and 82d; turn members 83 and 84 turn outward the toy vehicle 80 due to their dead weights: the toy vehicle 80 starts to be turned about a turn shaft 44 of the first arm 40; the turn members 83 and 84 that have turned outward the toy vehicle 80 come into contact with guide members 60 and 62 to be inverted; the tunably connected members 82a, 82b, 82c and 82d in contact with the second arm 50 are inverted; and thereby the toy vehicle 80 transforms from either the first or second vehicle form to the another vehicle form.