PURPOSE: To provide a FIFO type memory capable of responding to the temporary, intermittent, cyclical and high-speed accessing of data from the outside.

CONSTITUTION: A FIFO memory 1 constituted of RAM, a FIFO memory 2 constituted of cashe memory and a part for connecting the FIFO memories 1 and 2 are provided and data are transferred from the memory 1 to the memory 2 only when the memory 1 is not empty and the memory 2 is not full. Or, a part 4 for connecting the memories 1 and 2 is provided and data are transferred from the memory 2 to the memory 1 only when the memory 2 is not empty and the memory 1 is not full. Or, a part 5 for connecting the memories 1 and 2 is provided, writing data is written in the memory 2 from the outside when the memory 1 is empty and the memory 2 is not full and data are transferred from the memory 1 to the memory 2 when the memory 1 is not empty and the memory 2 is not full.