PURPOSE: To provide a diaper capable of fitting on body shape of wearer and preventing effectively the leakage and slip down without the oppression by having elastic side panels and mounting elastic members near the waist opening part and at the waist part.

CONSTITUTION: A main body 1 comprises an abdomen side part positioned on the abdomen side of wearer when worn, a back side part positioned on the back side and a crotch part. Elastic side panels 20, 20' are fixedly connected to respective right and left edge parts of the abdomen side part and the back side part and the elastic side panels 20 in the abdomen side part and the elastic side panel 20' in the back side part are fixedly connected to form waist opening part 15 and a pair of right and left leg opening parts 17, 17'. Elastic members 23, 23'; 21, 21' are used near the waist opening part D on the abdomen side part and the back side part and a waist part E positioned on the waist of the wearer when worn so that substantially continuous gathering is formed on the abdomen side part and back side part over the whole edge of the diaper through the elastic side panels 20, 2O'.