A process for producing a highly anticorrosive rare earth permanent magnet, characterized by sequentially subjecting an R—Fe—B sintered magnet to surface finishing involving cutting and/or polishing, plating pretreatment, nickel electroplating to a given plating thickness, immersion in an aqueous solution containing a phosphoric salt, washing with water and heat treatment at 150° to 400° C. for 1 to 24 hr in an atmosphere of 1.3×103 Pa or higher oxygen partial pressure so as to form a thin nickel oxide layer at the surface layer portion.