A novel activated carbon membrane with carbon whiskers (W-ACM) for wastewater and drinking water treatments was designed and prepared. This membrane has carbon whiskers on its surface for preventing the deposition and accumulation of particles and has activated carbon layer below its carbon whiskers for the adsorption of dissolved organics. Adsorption capacity of the membrane was compared with a granular activated carbon and an activated carbon fiber by using phenol. Prevention of the particle deposition on the membrane surface was elucidated by the filtration of water containing polymethyl methacrylate (PMMA). In this filtration, the carbon whiskers on the activated carbon membrane significantly extended the membrane lifetime, because of preventing the particle deposition on/within the membrane pores. From these results, this novel membrane can be a promising tool for the hybrid processes for wastewater and water treatment with long lifetime.