Abstract: Method of producing a film having a particle-containing layer, comprising the steps of: preparing a coating fluid in a tank, the coating fluid containing particles; conveying the coating fluid from the tank, discharging the coating fluid, and supplying the coating fluid to a supply port of a coating head including a manifold and a slot, the manifold having the supply port and a discharge port; supplying the coating fluid from the slot of the coating head to a continuously-running support; and suctioning part of the coating fluid from the discharge port of the manifold of the coating head by using a reciprocating pump including a non-return valve and discharging a pulsating flow from the reciprocating pump, wherein pressure adjustment is made so that a pressure on a discharge side of the reciprocating pump is always higher than a pressure on a suction side.