A fuel tank valve having: a housing that is arranged in a fuel tank and has a communication port communicating with an outside of the fuel tank; and a float valve body that is installed in the housing and closes the communication port when fuel in the housing increases, where a wall part of the housing has an opening part through which the fuel flows in and out, and a projecting part that is formed to correspond to the opening part and projects outwardly from the wall part, and the projecting part is separated above from the opening part by a predetermined distance, is provided.