PURPOSE: To obtain a large FRP board heating plate generating no warping by providing an insulating layer on the surface of a conductive layer avoiding an electrode and a connection of the electrode to the outer side.

CONSTITUTION: An FRP board plate 1 is provided with a conductive layer 2. On the surface of the conductive layer 2, an insulating layer 4 is provided avoiding an electrode 3 and its connection to the outer side. The FRP is so- called fiber reinforced plastics, and a heat resisting fiber such as a glass fiber, a carbon fiber, and a polyimide is used as its fiber. A heat resisting resin such as a thermosetting resin and the polyimide is used as its resin component.