The present invention relates to a rudder for a ship which is rotatably installed on a rudder horn disposed on a rear portion of a ship to control an advancing direction of the ship. The rudder for a ship includes: an upper rudder plate of fiber reinforced plastic (FRP) material; an upper metal plate coupled to a frontal lower portion of the upper rudder plate; an upper coupling plate of steel material coupled to a frontal upper portion of the upper rudder plate coupled to the upper metal plate by a first bolt penetrating the upper rudder plate; an upper rotary shaft of steel material having an upper end portion rotatably installed in an upper portion of the rudder horn having an upper fixating plate formed on a lower end portion to correspond to the upper coupling plate coupled to the upper coupling plate by a second bolt; a lower rudder plate of FRP material disposed to be apart below the upper rudder plate; a lower rotary shaft of steel material having a lower end portion penetrating the frontal upper portion of the lower rudder plate downward to rotatably be installed on the lower portion of the rudder horn, and having a lower metal plate formed on an upper end portion coupled to the frontal upper portion of the lower rudder plate by a third bolt; a plurality of horizontal members of FRP material vertically spaced apart from each other to be disposed between the upper rudder plate and the lower rudder plate; an impact absorption member of polyurethane foam material formed to fill a gap between the upper rudder plate and the lower rudder plate; and a side surface member of FRP material stacked to embrace the horizontal members between the upper rudder plate and the lower rudder plate, and an exposed side surface of the impact absorption member.
