A method for producing water absorbent polyacrylic acid (salt) resin powder, comprising the steps of: (i) polymerizing an acrylic acid (salt) monomer aqueous solution; (ii) during or after the step of (i), performing gel grinding carried out with gel grinding energy (GGE) of 9 [J/g] to 40 [J/g] of a hydrogel crosslinked polymer obtained by the polymerization, wherein the hydrogel crosslinked polymer has resin solid content of 10 wt% to 80 wt%; (iii) drying a particulate hydrogel crosslinked polymer obtained by the gel grinding, wherein the drying is performed at 150°C to 250°C by use of a drier which is a through-flow belt drier and a velocity of hot air is 0.8 [m/s] to 2.5 [m/s] in a direction vertical to the particulate hydrogel crosslinked polymer; and (iv) carrying out a surface treatment to the particulate hydrogel crosslinked polymer thus dried, where the gel grinding energy is calculated by the following Expression: GGE 2 J / g = √ 3 × voltage × current during gel grinding − current during idling × power factor × motor efficiency / weight of hydrogel crosslinked polymer to be supplied into gel grinding device for one second where "power factor" and "motor efficiency" are values during gel grinding and are respective characteristic values for the gel grinding device in a range of 0 to 1, which values change depending on an operation condition etc. of the gel grinding device, voltage unit is, current unit is, and unit of weight of the hydrogel crosslinked polymer is [g/s], "√3" in Expression is used in a case where the gel grinding device is driven by a three-phase alternating current power supply and, in a case where the gel grinding device is driven by a single-phase alternating current power supply, the gel grinding energy is calculated by replacing "√3" with "1". (i) polymerizing an acrylic acid (salt) monomer aqueous solution; (ii) during or after the step of (i), performing gel grinding carried out with gel grinding energy (GGE) of 9 [J/g] to 40 [J/g] of a hydrogel crosslinked polymer obtained by the polymerization, wherein the hydrogel crosslinked polymer has resin solid content of 10 wt% to 80 wt%; (iii) drying a particulate hydrogel crosslinked polymer obtained by the gel grinding, wherein the drying is performed at 150°C to 250°C by use of a drier which is a through-flow belt drier and a velocity of hot air is 0.8 [m/s] to 2.5 [m/s] in a direction vertical to the particulate hydrogel crosslinked polymer; and (iv) carrying out a surface treatment to the particulate hydrogel crosslinked polymer thus dried, where the gel grinding energy is calculated by the following Expression: GGE 2 J / g = √ 3 × voltage × current during gel grinding − current during idling × power factor × motor efficiency / weight of hydrogel crosslinked polymer to be supplied into gel grinding device for one second where "power factor" and "motor efficiency" are values during gel grinding and are respective characteristic values for the gel grinding device in a range of 0 to 1, which values change depending on an operation condition etc. of the gel grinding device, voltage unit is, current unit is, and unit of weight of the hydrogel crosslinked polymer is [g/s], "√3" in Expression is used in a case where the gel grinding device is driven by a three-phase alternating current power supply and, in a case where the gel grinding device is driven by a single-phase alternating current power supply, the gel grinding energy is calculated by replacing "√3" with "1". the gel grinding energy is calculated by the following Expression: GGE 2 J / g = √ 3 × voltage × current during gel grinding − current during idling × power factor × motor efficiency / weight of hydrogel crosslinked polymer to be supplied into gel grinding device for one second where "power factor" and "motor efficiency" are values during gel grinding and are respective characteristic values for the gel grinding device in a range of 0 to 1, which values change depending on an operation condition etc. of the gel grinding device, voltage unit is, current unit is, and unit of weight of the hydrogel crosslinked polymer is [g/s], "√3" in Expression is used in a case where the gel grinding device is driven by a three-phase alternating current power supply and, in a case where the gel grinding device is driven by a single-phase alternating current power supply, the gel grinding energy is calculated by replacing "√3" with "1". where "power factor" and "motor efficiency" are values during gel grinding and are respective characteristic values for the gel grinding device in a range of 0 to 1, which values change depending on an operation condition etc. of the gel grinding device, voltage unit is, current unit is, and unit of weight of the hydrogel crosslinked polymer is [g/s], "√3" in Expression is used in a case where the gel grinding device is driven by a three-phase alternating current power supply and, in a case where the gel grinding device is driven by a single-phase alternating current power supply, the gel grinding energy is calculated by replacing "√3" with "1".