Provided is a process by which an electret material having excellent thermal resistance of charge retentivity can be obtained. The process for producing an electret material of the invention includes an irradiation step, a formation step, and a charging step. In the irradiation step, a dispersion containing fine polytetrafluoroethylene particles is irradiated with γ rays. In the formation step, the dispersion which has been irradiated with γ rays is applied to an electrode plate and then dried, and the fine polytetrafluoroethylene particles are sintered to form a polytetrafluoroethylene layer on the electrode plate. In the charging step, the surface of the polytetrafluoroethylene layer is subjected to a charging treatment.