The present invention relates to an ejector assembly and a vacuum pump, the ejector assembly including a typical cylindrical vacuum ejector and a support part. The support part includes a first support having a supply line extending outwards from a hole in which a first end of the ejector is mounted, and a second support having a discharge line extending outwards from a hole in which a second end of the ejector is mounted. Further, the first and second supports facing each other are configured such that the outer circumferential surfaces thereof are in contact with the inner circumferential surface of a pipe member so as to form a space between the first and second supports, the space communicating with through holes. In the vacuum pump using the ejector assembly, the pipe member is a housing, and the space is a vacuum chamber formed in the housing.