Door closure device

The present invention provides a door closure device, wherein a closing device body 2a is provided to either of the door body 11 and a door frame 12, a tentative fastening means 25 is provided to the other. The closing device body 2a comprises a rotatable arm 21 within a range between an opening position O and a closing position C, an energizing means 23 energizing on the arm 21 and a buffer means 24 decelerating rotational operation of the arm 21 are provided to the closing device body 2a, the tentative fastening means 25 is abutted on a fixed section 21b of the arm 21, it can be held so as to become immobile in the rotational direction of the arm 21, and when there is the door body 11 between the predetermined opening position and the closing position, the fixed section 21b is held by the tentative fastening means 25, and the closing device of the sliding door closing the door body 11 is provided.