By a process for producing a porous carbon material from a plant-derived material as a raw material, said process including carbonizing the plant-derived material at 800.degree. C. to 1,400.degree. C. and then applying a treatment with an acid or alkali, a porous carbon material having a value of specific surface area of at least 10 m.sup.2/g as measured by the nitrogen BET method, a silicon content of at most 1 wt % and a pore volume of at least 0.1 cm.sup.3/g is obtainable from a plant-derived material, which has a silicon content of at least 10 wt %, as a raw material. Also provided is a process for producing a porous carbon material equipped with excellent functionality so that the porous carbon material can be used, for example, as an anode material for batteries, an adsorbent, masks, adsorbing sheets, or carriers.