PURPOSE: To constantly hold and support an object to be packed while being positioned at the center without play by rotatably providing support bodies on right and left of a support bottom and sidewall plates outside on right and left.

CONSTITUTION: A support body 22 largely opens its right and left sidewall plates 22B outward waiting for a bag 2b carried, wherein with the bag 2B carried upward a fastener is released by a separate holding part 16, and the bag 2b containing an object to be packed is mounted on a support bottom 22A of the support body 22. At this time, a support body open/close driver 221 is driven to push a link coupling 22K protruding on an outer face of the sidewall plate 22B via a link 22J to allow both right and left sidewall plates 22B to stand. Thus the right and left sidewall plates 22B stand inward to be closed and hold the bag 2B with the object contained. Closing of the sidewall plates 22B allows the object to be constantly caught at the center without corrupting the bag 2B, thereby holding the bag 2B for positioning and supporting.