Technical or formal term for an elevator or lift; in everyday conversation, エレベーター is far more common.
See also: エレベーター
An elevator is installed in this building.
昇降機の定期点検を行います。
We will perform a regular inspection of the elevator.
stairlift; chair lift for stairs
Compound of 昇降 (shōkō, 'ascending and descending') + 機 (ki, 'machine'). The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning.