An information recording medium (100) is provided with: a user data area (108) for recording therein record data; a plurality of temporary defect management areas (104, 105) for temporarily recording therein defect management information (120) which is a basis of defect management for a defect in the data area; and a flag area (111) for recording therein distinction information for distinguishinga temporary defect management area in which the defect management information that is effective is recorded, from the plurality of temporary defect management areas, the distinction information beingrecorded as a type of a combination pattern of an area set to be in a recorded condition and an area left to be in an unrecorded condition according to a predetermined rule, in the flag area.