A three-dimensional powder bed fusion additive manufacturing apparatus includes a determination unit that determines presence or absence of powder scattering in a second preheating step using at least a third image that is an image of a powder layer photographed by a camera after the second preheating step among a first image that is an image of the powder layer photographed by the camera after a first preheating step, a second image that is an image of the powder layer photographed by the camera after the powder application step, and the third image.