A spacer forming device according to the present invention includes glass plate fixing means for fixing one glass plate, an applicator head for applying a spacer forming material, spacer forming material supply means having an extruding means that extrudes the spacer forming material while melting and mixing the material and a fixed displacement pump for supplying the spacer forming material extruded from the extruding means to the applicator head, and an articulated robot that moves the applicator head along the periphery of the one glass plate. By using the spacer forming device, the spacer forming material is applied from the applicator head along the periphery of the upper surface of the one glass plate thereon to form a spacer.