To provide a door closer which prevents a strange noise from being generated because a slider and a rail abut on each other.

A door closer includes a door closer body, an arm which is pivotally connected to the door closer body, a slider 20 which is pivotally connected to a tip of the arm, and a rail for slide-guiding the slider 20. A side surface 20c of the slider 20 facing a side wall of the rail is provided with clearance elimination means. The clearance elimination means comprises a spacer 25 and a leaf spring, and the spacer 25 can move in the width direction of the slider 20 against the leaf spring.