Abstract: An air cylinder damper device in combination with a storage cabinet includes a cylinder body having a front terminal opening, a piston slidably disposed inside the cylinder body, a spring member disposed inside the cylinder body for biasing the piston in a shutting direction of the storage cabinet, a string member having one terminal part thereof connected to the piston within the cylinder body, and a cap provided on the front terminal opening of the cylinder body and having a curved peripheral guide face capable of guiding the string member in the direction of disposition thereof. The opening motion of the storage cabinet is controlled by moving the piston in one direction through the string member against the biasing force of the spring member. The shutting motion of the storage cabinet is controlled by moving the piston in the opposite direction with to the biasing force of the spring member.