A vacuum apparatus of rotary motion entry is disclosed, which comprises: a shaft sleeve, disposed on a cavity wall of a vacuum system; a rotary shaft, ensheathed by the shaft sleeve; and a transmission set, connected to the rotary shaft for driving the same; wherein, the rotary shaft is disposed passing through a hole formed on the base of the shaft sleeve while there are a first bearing, a second bearing, a sealing ring and a shaft seal being arranged separately inside the hole. Moreover, the shaft seal has a flake-like lip flange formed extending toward the center of the hole, that is capable of being extended away from the vacuum system by the inserting of the rotary shaft into the hole, and thereby, enabling the lip flange to engage with the rotary shaft tightly by the atmospheric pressure and thus isolating the outside world from the vacuum system.