A memory card control device includes an insertion unit to which a memory card is inserted, a memory card controller to control writing and reading of data to/from the memory card inserted in the insertion unit, an interface controller to send and receive the data written or read to/from the memory card to/from a host computer, a clock supplier to supply a clock signal to the memory card controller and the interface controller, a memory card detector to detect presence or absence of the memory card inserted in the insertion unit, and a low power consumption mode switching unit to switch the memory card controller and the interface controller to a low power consumption mode in response to the absence of the memory card detected by the memory card detector.