To provide an apparatus for preventing a warp of a printed circuit board in a reflow device, that can bring support pins into point contact with the reverse side of the printed circuit board so as to minimize a contact area without using a large-scale warp preventing mechanism and that can easily and surely prevent the printed circuit board from warping.

For the purpose of preventing interference on electronic components 80 already mounted on the reverse side of the printed circuit board P, at the time of its transportation inside a reflow device 2, there are arranged the support pins 36 (stopper pins 36a and support pins 36b) in an arbitrary position coordinate. In addition, the support pins 36 (support pins 36b) are brought into point contact with the reverse side of the printed circuit board P so that the contact area is minimized.