A panel for concrete castings is composed of at least a supporting layer made of wood which is at least partly externally coated with one or more sealing layers and wherein the supporting layer is in turn composed of at least two layers made of wood strips or sheets which are glued together and whose wood fibres for each layer have the same and parallel orientation said strips or sheets being oriented with reference to the peripheral edges of the panel such that at the end edges and at the longitudinal edges of said supporting layer a portion of the wood fibres are parallel and a portion of the wood fibres are transverse to said side. At the longitudinal sides the wood fibres ending perpendicular to or transverse to said sides are not covered from the environment for an amount not greater than 40% of the overall surface of said longitudinal edges of the supporting layer, while at least a part of one end side of the panel that is at least a side transverse to said longitudinal sides of the panel has or is composed of a sealing edge which is made of plastic material, and it overlies said end side of the supporting layer and/or of the sealing/protective layer or layers along at least said part of said end side and it is fastened to said end side of the panel by chemical/physical bonding and it seals it from the environment.