A heat source isolation mechanism of the laminate molding device includes an intermediate table that is mounted on an upper surface of a main table, an auxiliary table which is provided on an upper surface of the intermediate table and of which a temperature can be adjusted, and a bellows member in which the auxiliary table is disposed and which includes a lower end that is provided on the intermediate table and an upper end that is mounted on the peripheral wall, and which expands as the main table is lowered. The bellows member is made of an insulating material. The recoater head supplies a metal material powder to a molding area inside the bellows member and a powder layer is formed on the auxiliary table, a laser emission unit emits a laser beam to a predetermined area of the powder layer and sintering is performed.