NOVELTY - A pure-water purification apparatus (1) has purification portion (21) in which ion-exchange resin (C) which contacts pure water (W) supplied to pure-water utilization apparatus and removes impurities from the pure water is filled, cation supply portion (11) formed by filling antimicrobial material (A), in container (10) through which pure water passes, and cation capture portion formed by filling with noble-potential material (B). The noble-potential material exhibits natural electrical potential nobler than the antimicrobial material when contacting pure water.    USE - Pure-water purification apparatus is used for fuel cell system (claimed).    ADVANTAGE - The increase in load of ion-exchange resin for removing impurity of pure water is prevented and antibacterial treatment is carried out respect to pure water, when using the pure-water purification apparatus.    DETAILED DESCRIPTION - A pure-water purification apparatus has purification portion in which ion-exchange resin which contacts pure water supplied to pure-water utilization apparatus and removes impurities from the pure water is filled, cation supply portion formed by filling antimicrobial material which has antimicrobial property and elutes cation with respect to the pure water in a state at which the pure water contacts, in container (10) through which the pure water passes, and cation capture portion formed by filling with noble-potential material electrically connected with the antimicrobial material in container (20) through which the pure water passes. The noble-potential material exhibits natural electrical potential nobler than the antimicrobial material when contacting pure water. The cation capture portion is arranged in downstream of the cation supply portion, and upstream of the purification portion. The cation supply portion is arranged in upstream of the purification portion. An INDEPENDENT CLAIM is included for fuel cell system.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the fuel cell system containing the pure-water purification apparatus.    Pure-water purification apparatus (1)    Containers (10,20)    Cation supply portion (11)    Cation capture portion (12)    Purification portion (21)    Fuel cell (80)    Antimicrobial material (A)    Noble-potential material (B)    Ion exchange resin (C)    Pure water (W)