To provide a manufacturing method capable of providing an electret material having an excellent charge-retentive property with respect to heat.

The method for manufacturing an electret material includes: an irradiation step, a formation step and a charging step. In the irradiation step, a dispersion containing polytetrafluoroethylene microparticles is irradiated with γ-ray. In the formation step, the dispersion that has been irradiated with γ-ray is applied on an electrode plate, and thereafter dried, and the polytetrafluoroethylene microparticles are baked, thereby forming a polytetrafluoroethylene layer on the electrode plate. In the charging step, the surface of the polytetrafluoroethylene layer is subjected to a charging treatment.