Water absorbent resin powder comprising a polyacrylic acid (salt)-based water absorbent resin as a main component, the water absorbent resin powder satisfying the following (A) to (C):(A) the water absorbent resin powder containing particles smaller than 150 µm in a ratio of 0 mass-% to 4.5 mass-% before an impact resistance test, and the water absorbent resin powder containing, in a ratio of 0 mass-% to 4.5 mass-%, particles smaller than 150 µm and increased by the impact resistance test；(B) the water absorbent resin powder having a saline flow conductivity (SFC) of not less than 10； and(C) the water absorbent resin powder having a thermal conductivity of not more than 125 [mW/(m·K)].
