This diaper (50B) is a disposable pants type diaper which is provided with an outer body (3) forming the outer surface and in which a pair of side sealed parts (4 4) a waist opening part (8) and a pair of leg opening parts (9 9) are formed by joining the right and left edges of the outer body (3) in the front body section (F) and the right and left edges of the outer body (3) in the rear body section (R) wherein the side sealed parts (4) have sealed edge parts (41) in which the edge part (3F) of the outer body in the front body section and the edge part (3R) of the outer body in the rear body section are joined at a fused part in the form of a continuous line extending in the lengthwise direction of the side sealed parts and the side sealed parts (4) partially have a non sealed part (42) in which the edge part (3F) of the outer body in the front body section and the edge part (3R) of the outer body in the rear body section face one another in a non joined state.
