The present invention provides a water absorbing agent which is excellent in its water absorbing physical properties, in particular water absorbing speed, and has a great bulk specific gravity. Specifically, the water absorbing agent according to the present invention comprises a polyacrylic acid (salt)-based water absorbent resin as a main component, and has a Hausner ratio of less than 1.18 and a water absorbing speed (FSR) of 0.25 [g/g/s] or more. Furthermore, the water absorbing agent (i) has a bulk specific gravity of 0.61 g/ml to 0.80 g/ml, or (ii) further comprises a surfactant whose HLB is 1 to 6.
