The present invention has an object to provide a method for inexpensively and stably producing, with high productivity, water absorbent resin having excellent damage resistance, and is 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.
