Provided is a tunnel thruster of a ship. According to an embodiment of the present invention, the tunnel thruster of a ship has a tunnel connected to an outlet formed on the side, and includes: a body which has a duct funneled with the tunnel installed inside the ship with the ability to rotate; a propeller installed inside the duct; and a motor which rotates the propeller. The rotation of the body selectively connects an inlet formed under the bottom of the ship with the tunnel.
