Abstract: An apparatus is usable to manufacture a filter. The apparatus includes a pleats-forming unit, a first belt part, a second belt part, and a controller. The pleats-forming unit delivers a filter substrate in a first direction and then successively folds the filter substrate into alternate mountains and valleys. The first belt part is disposed downstream of the pleats-forming unit in the first direction. The first belt part contacts with the mountains and valleys of the filter substrate to compress the mountains and valleys of the filter substrate in the first direction. The second belt part is disposed downstream of the first belt part in the first direction. The second belt part pulls the mountains and valleys of the filter substrate in the first direction to form a predetermined pitch between each adjacent pair of the mountains or valleys. The control unit controls a traveling speed of the second belt part.