A method of making water absorbing resin according to the present invention includes a polymerization step for producing a water absorbing resin by reverse-phase suspension polymerization; and a drying step for drying the water absorbing resin obtained in the polymerization step. In the drying step, the drying is made by using a dryer (X1) which includes: an end wall (21), an opposite end wall (22), a circumferential wall (23) and a rotation shaft (24) between these end walls, stirring means (25) provided in the rotation shaft (24) for stirring the water absorbing resin while moving the resin from the end wall (21) to the end wall (22), and stirring means (26) provided in the rotation shaft (24) between the stirring means (25) and the end wall (22) for stirring the water absorbing resin while moving the resin from the end wall (22) to the end wall (21).