Vacuum generators and ejectors are machines that generate a vacuum. Vacuum generation methods are different, and vacuum generators are used to create a vacuum using compressed air and carry it by suction. When the compressed air flows into the diffuser, it is jetted at a high speed and the pressure drops, creating a vacuum. It is composed of a nozzle and a diffuser, and the degree of the vacuum pressure changes depending on the shape and dimensions. Ejectors, on the other hand, use water, steam, oil, etc. to create a vacuum. This is a mechanism in which the material that has been heated and turned into steam is injected at a high speed, so that the lower stage is compressed. It consists of jets, cylinders, boilers, pipe heaters, heat insulators with different widths, etc. The ejected steam is cooled and returns to the boiler again. Shapes and performances vary depending on the type, such as those with a solenoid valve, elbow type, and compact type.