A method is disclosed for inexpensively and stably producing, with high productivity, water absorbent resin having excellent damage resistance. A method for producing a polyacrylic acid (salt)-based water absorbent resin, the method comprising a surface-crosslinking step, the surface-crosslinking step including a reaction step, the reaction step involving using a reactor having (i) an inner wall surface having a temperature within a range of 100° C. to 250° C. and (ii) an inside atmosphere having a dew point within a range of 60° C. to 100° C., the reaction step including heat-treating a water absorbent resin mixture so as to produce water absorbent resin powder having a temperature within a range of 90° C. to 130° C.
