An image forming apparatus includes a recording head, a liquid tank, a first fluid flow path supplying liquid to the recording head, a second fluid flow path being in communication with the liquid tank, a pressure adjusting valve allowing fluid communication between the first and the second fluid flow paths, a cap member covering a nozzle surface of the recording head, and a suction unit being in communication with the cap member. The pressure adjusting valve includes a movable member movably disposed in the internal fluid flow path, wherein the movable member includes a sealing unit that seals the communication between the first and the second fluid flow paths when the cap member covers the nozzle surface of the recording head and a negative pressure is generated in a cap-member space formed between the cap member and the nozzle surface by driving the suction unit.