To provide a building board which enables a person such as a worker laying the building board to easily check the indication of various kinds of pieces of information on the building board with no oversight.

One end of the building board is provided with a tongue 2; the other end thereof is provided with a groove 3; and the building boards are laid in a state in which the tongue 2 and the groove 3 are fitted into each other. An information indication portion 4 is provided on the front side of the tongue 2. Thus, since the information indication portion 4 is provided on the front side of the building board 1, the person such as the worker laying the building board can easily check the information indication portion 4. Additionally, since a surface of the tongue 2 provided with the information indication portion 4 is concealed by being fitted into the groove 3 of another building board 1 during the laying of the building boards 1, the information indication portion 4 cannot be seen from the outside after the laying of the building boards 1.