A device that smoothes out wrinkles of a composite body of a continuous sheet, in a state a polymeric material is overlapped to a central portion in a width direction of the continuous sheet that travels, to which a depression is shaped at the central portion by a protruding member being pressed against the central portion from the continuous sheet side. The wrinkle smoothing device for a composite body of a continuous sheet related to an absorbent article includes a first belt that moves along a first travel path while retaining the central portion of the continuous sheet a second belt that is provided adjacent the first belt on one side in the width direction thereof, and moves along a second travel path while retaining a portion at the one side from the central portion of the continuous sheet and a third belt that is provided adjacent the first belt on an other side in the width direction thereof, and moves along a third travel path while retaining a portion at the other side from the central portion of the continuous sheet, wherein the second travel path is inclined from the first travel path such that a downstream side is more spaced apart from the first travel path to the one side in the width direction than the upstream side, the third travel path is inclined from the first travel path such that a downstream side is spaced more apart from the first travel path to the other side in the width direction than the upstream side, the second belt retains a portion on the one side of the continuous sheet while relatively sliding in the width direction of the continuous sheet, and the third belt retains a portion on the other side of the continuous sheet while relatively sliding in the width direction of the continuous sheet.
