A lightning-resistant fastener, a cap, a fastener member, and a method for attaching the lightning-resistant fastener are provided, which enhance workability and quality stability besides reliably securing an insulating property, and can lead to enhancement in safety of an airframe and reduction in manufacturing cost. A head portion 25b of a fastener main body 25 includes a head cap 50, and a shaft portion 25s of the fastener main body 25 includes a shaft cap 30, whereby a direct strike of lightning to a fastener member 24, and occurrence of an arc discharge from the fastener member 24 in the case of a lightning strike can be suppressed. A hole 52 is formed in the head cap 50, and a thread groove 52a is formed in the hole 52, whereby the head cap 50 can be reliably and easily positioned and attached to the fastener member 24.