Absorbent article

An absorbent article comprising a top sheet on the skin contact side, a back sheet on the non-skin contact side, and an absorbent body situated between the two sheets:

• wherein the absorbent body comprises a bulky absorbent sheet, and
• the bulky absorbent sheet comprises heat-expanding particles that are dispersed in the bulky absorbent sheet and have been expanded by heat,
• wherein the bulky absorbent sheet has a density of 0.025-0.1 g/cm3 and comprises:
• a blended sheet comprising the heat-expanding particles dispersed in a fiber starting material from a paper-making starting material, in which the fiber starting material comprising 30-100 mass % of natural pulp and 0-70 mass % of other fiber, and the heat-expanding particles having an initial mean particle size of 5-30 μm are dispersed at a proportion of 5-30 parts by mass of the heat-expanding particles having the initial particle size per 100 parts by mass of the fiber starting material, and in which at least some of the heat-expanding particles being expanded by heat to a 20-125 fold volume,
• wherein the Klemm water absorption degree of the bulky absorbent sheet is at least 10 mm, the percentage reduction in wet compressive bulk is no greater than 50%, and the wet compressive residual strain is no greater than 30%.