Abstract: Provided herein is an oscillating water column type wave energy converting apparatus that is suspended underwater by a mooring device and system thereof, the apparatus and system comprising an damping plate connected to the mooring device; a post with a hollow of which both ends are open, the post extending vertically upwards from the mooring device; a turbine disposed inside the hollow of the post; and a housing of which its lower end is open and which is disposed at an upper portion of the post, wherein the turbine is rotated by air that flows according to changes in water level inside the hollow of the post.