A wind turbine blade having a lightning protection function, characterized in that it comprises: an outer shell; a spar arranged in a space inside the outer shell and extending in a longitudinal direction of the blade; a spar cap which is formed by a carbon-fiber plastic laminated member disposed on a blade root side and a glass-fiber plastic laminated member disposed on a blade tip side that are connected together, said spar cap supporting the spar to the outer shell; and a lightning protection unit comprising: a receptor (21,23) for receiving lightning which is provided in the outer shell on the blade tip side where the glass-fiber plastic laminated member is arranged; a down conductor for directing lightning current received by the receptor (21,23) into the ground or the water; a conductive metal member which covers the outer shell on the blade root side where the carbon fiber plastic laminated member is arranged; and a base plate which is disposed in the wind turbine blade and to which the receptor (21, 23) is attached and connected, wherein said conductive metal member is electrically connected to said down conductor, and wherein the glass-fiber plastic laminated member is connected to the carbon-fiber plastic laminated member at a connection part which is arranged at 1/8 to 1/2 of an entire length of the wind turbine blade from a blade tip, the carbon-fiber plastic laminated member forming a portion of the spar cap which is only on the blade root side with respect to the connection part, the glass-fiber plastic laminated member forming a portion of the spar cap which is only on the blade tip side with respect to the connection part, wherein the receptor (21, 23) is installed in the outer shell only on the blade tip side where the glass-fiber plastic laminated member is arranged, the receptor (21, 23) being exposed to an outer surface of the outer shell, wherein the receptor (21, 23) is connected to the down conductor via the base plate. an outer shell; a spar arranged in a space inside the outer shell and extending in a longitudinal direction of the blade; a spar cap which is formed by a carbon-fiber plastic laminated member disposed on a blade root side and a glass-fiber plastic laminated member disposed on a blade tip side that are connected together, said spar cap supporting the spar to the outer shell; and a lightning protection unit comprising: a receptor (21,23) for receiving lightning which is provided in the outer shell on the blade tip side where the glass-fiber plastic laminated member is arranged; a down conductor for directing lightning current received by the receptor (21,23) into the ground or the water; a conductive metal member which covers the outer shell on the blade root side where the carbon fiber plastic laminated member is arranged; and a base plate which is disposed in the wind turbine blade and to which the receptor (21, 23) is attached and connected, a receptor (21,23) for receiving lightning which is provided in the outer shell on the blade tip side where the glass-fiber plastic laminated member is arranged; a down conductor for directing lightning current received by the receptor (21,23) into the ground or the water; a conductive metal member which covers the outer shell on the blade root side where the carbon fiber plastic laminated member is arranged; and a base plate which is disposed in the wind turbine blade and to which the receptor (21, 23) is attached and connected, wherein said conductive metal member is electrically connected to said down conductor, and wherein the glass-fiber plastic laminated member is connected to the carbon-fiber plastic laminated member at a connection part which is arranged at 1/8 to 1/2 of an entire length of the wind turbine blade from a blade tip, the carbon-fiber plastic laminated member forming a portion of the spar cap which is only on the blade root side with respect to the connection part, the glass-fiber plastic laminated member forming a portion of the spar cap which is only on the blade tip side with respect to the connection part, wherein the receptor (21, 23) is installed in the outer shell only on the blade tip side where the glass-fiber plastic laminated member is arranged, the receptor (21, 23) being exposed to an outer surface of the outer shell, wherein the receptor (21, 23) is connected to the down conductor via the base plate.