An absorbent article may include a top sheet that is liquid-permeable, a back sheet that is liquid-impermeable, and an absorbent body situated between the top sheet and the back sheet in a thickness direction. At least one of the top sheet and the back sheet may include a synthetic resin sheet that includes a synthetic resin component and an oxidative decomposer comprising a mixture of a carboxylate and a rare earth compound. The synthetic resin sheet may contain the oxidative decomposer in a mass ratio such that a decomposition rate index (Di), as determined by formula (1), is 7.8 or less: Di=Br×Sa  (1) where Br represents a mass ratio (g/g) of the oxidative decomposer with respect to the synthetic resin component, and Sa represents a specific surface area (cm2/g) of the synthetic resin sheet.