PURPOSE: To prevent a substrate from being damaged and to position it with high accuracy regarding a substrate-positioning mechanism used to bond a semiconductor chip to the substrate.

CONSTITUTION: A heater 23 is installed in a main body 22, and a first fixed plate 25a and a second fixed plate 25b which correspond to adjacent sides are attached to a substrate 24 to be mounted on the heater 23. Then, the positioning mechanism is constituted in such a way that a first positioning plate 26a and a second positioning plate 26b are moved by a rotary actuator 34 via eccentric shafts 29a, 29b and plate springs 28a, 28b, that the substrate 24 is pushed to the first and second fixed plates 25a, 25b and that it is positioned and fixed.