Abstract: A method for producing a composite material including a fiber reinforced resin and a lightweight core adjacent thereto, is capable of preventing inflow of a resin into holes on the surface of the lightweight core without increasing the weight of the composite material and also capable of producing a composite material with a high molding accuracy and at a high production rate. In order to produce a composite material including a lightweight core and a fiber reinforced resin that is adjacent to at least a part of a surface of the lightweight core, the method includes arranging, inside a molding tool, a fiber base material adjacently to a foundry core which includes a part which has a part having a shape substantially the same as a shape of a part of the lightweight core which is adjacent to the fiber reinforced resin, which is performed first.