When there are very many images stored in a memory card, a time after a computer and a digital camera have been logically connected with each other until the computer and the camera answers a user becomes extremely long. When the digital camera caches the information of a file stored in a storage medium by accessing the storage medium in a reproduction mode, and when the digital camera and the computer are physically connected to each other and they are in a communication mode, information which the computer appears to request finally is generated and stored. After that, when the digital camera receives a data transfer request from the computer, the digital camera transmits stored information to the computer in a lump.