A vacuum device includes a processing target placement unit that is arranged inside a vacuum chamber and a vacuum evacuation unit that is connected to the vacuum chamber. The processing target placement unit has one main surface on which processing targets are placed and a side surface that is connected to the one main surface. The processing target placement unit is provided with a plurality of grooves that have openings at the one main surface. When the processing target placement unit is viewed from the one main surface side thereof, the smallest width of the opening of each groove in the one main surface is equal to or less than half the smallest width of the processing target.