When an alternating current is applied to a conductive slab, the induced current impedes the electric current and this causes skin effect for all conductive materials. For laminated Carbon Fiber Reinforced Plastics (CFRP), however, the skin-effect depth is not evaluated. In the present study, therefore, Maxwell’s equations are analytically solved, and the skin-effect depth of unidirectional CFRP is derived first. Using the result, skin-effect is analyzed for the laminated CFRP. As a result, the skin-effect depth is derived for the laminated CFRP, and the effect is compared with the newly defined skin-effect of direct current caused by strong anisotropic conductance. For the highly toughened CFRP that has resin rich layers, the skin-effect of the direct current is more important than that of alternating current.