A moving device for a vehicle comprising: a moving body; guide rails (14, 14L, 14R) which are a pair of guide rails (14, 14L, 14R) extending in a moving direction of the moving body on both sides in one direction orthogonal to the moving direction and in which each of the guide rails (14, 14L, 14R) has a first guide (21, 21L, 21R) and a second guide (22, 22L, 22R) which are mutually symmetrical in the one direction; a pair of connecting portions that are provided at both-side end portions of the moving body in the one direction and are mutually symmetrical in the one direction; a first shoe that is mounted on one of the two connecting portions in an engagement state and slides the first guide (21, 21R) of the guide rail (14, 14R) on the corresponding side; a second shoe that is mounted on the other of the two connecting portions in an engagement state, slides the second guide (22, 22L) of the guide rail (14, 14L) on the corresponding side, and has the same shape as that of the first shoe; wherein the first shoe and the second shoe respectively comprise a substantially arcuate side flexure portion; characterized by comprising a first drive belt that is connected to the first shoe in the first guide (21, 21R) to be integrally moved and moves and drives the first shoe; and a second drive belt that is connected to the second shoe in the second guide (22, 22L) to be integrally moved and moves and drives the second shoe; the first shoe and the second shoe respectively have a substantially arcuate upper flexure portion elastically coming into contact with a lower surface of the ceiling wall of the guide rails (14R, 14L); wherein each of the guide rails (14, 14L, 14R) comprises a third guide interposed between the first guide (21, 21L, 21R) and the second guide (22, 22L, 22R) in the one direction, wherein the first shoe and the second shoe respectively slide the third guide of the guide rail (14, 14L,14R) of the corresponding side; the third guide for the first shoe and the third guide for the second shoe respectively comprise slip-off preventing pieces (14f, 14g); the side flexure portion of the first shoe elastically comes into contact with a surface of an upper wall and the slip-off preventing piece of the guide rail on the vehicle inside; and the side flexure portion of the second shoe elastically comes into contact with a surface of an upper wall and the slip-off preventing piece of the guide rail on the vehicle outside. a moving body; guide rails (14, 14L, 14R) which are a pair of guide rails (14, 14L, 14R) extending in a moving direction of the moving body on both sides in one direction orthogonal to the moving direction and in which each of the guide rails (14, 14L, 14R) has a first guide (21, 21L, 21R) and a second guide (22, 22L, 22R) which are mutually symmetrical in the one direction; a pair of connecting portions that are provided at both-side end portions of the moving body in the one direction and are mutually symmetrical in the one direction; a first shoe that is mounted on one of the two connecting portions in an engagement state and slides the first guide (21, 21R) of the guide rail (14, 14R) on the corresponding side; a second shoe that is mounted on the other of the two connecting portions in an engagement state, slides the second guide (22, 22L) of the guide rail (14, 14L) on the corresponding side, and has the same shape as that of the first shoe; wherein the first shoe and the second shoe respectively comprise a substantially arcuate side flexure portion; characterized by comprising a first drive belt that is connected to the first shoe in the first guide (21, 21R) to be integrally moved and moves and drives the first shoe; and a second drive belt that is connected to the second shoe in the second guide (22, 22L) to be integrally moved and moves and drives the second shoe; the first shoe and the second shoe respectively have a substantially arcuate upper flexure portion elastically coming into contact with a lower surface of the ceiling wall of the guide rails (14R, 14L); wherein each of the guide rails (14, 14L, 14R) comprises a third guide interposed between the first guide (21, 21L, 21R) and the second guide (22, 22L, 22R) in the one direction, wherein the first shoe and the second shoe respectively slide the third guide of the guide rail (14, 14L,14R) of the corresponding side; the third guide for the first shoe and the third guide for the second shoe respectively comprise slip-off preventing pieces (14f, 14g); the side flexure portion of the first shoe elastically comes into contact with a surface of an upper wall and the slip-off preventing piece of the guide rail on the vehicle inside; and the side flexure portion of the second shoe elastically comes into contact with a surface of an upper wall and the slip-off preventing piece of the guide rail on the vehicle outside.