An elevating apparatus of a table is disclosed. It mainly comprises a height adjusting apparatus having a gas spring inserted into an inner column of each of two legs respectively, a chute disposed outside the inner column and corresponding to a guide rail of a hollow outer column, a guide gear pivotally connected to a teeth-guiding slot of the hollow outer column, a gear rack disposed at one side of the inner column adjacent to the guide gear, and a pulley pivotally connected to a pulley slot of the hollow outer column for contacting the inner column, wherein two lateral sides of the chute are provided with plural arc portions equally spaced apart from each other for contacting the guide rail.