PURPOSE: To obtain a data transfer system by which transfer time can be shortened by efficiently performing access to both memory in the data transfer system between the memories including the one to which DMA(direct memory access) is applied.

CONSTITUTION: In the data transfer system between first memory 1 accessed by a memory control part 32 and second memory 2 accessed by a DMA control part 42 receiving a DMA request from a DMA request control part 52, a memory access request is issued from the DMA request control part 52 to the memory control part 32, and when a response for access permission is obtained, the standby for access to the first memory 1 by the memory control part 32 is instructed. Thence, the DMA request is issued from the DMA request control part 52 to the DMA control part 42, and when a DMA response for that is obtained, the standby of the memory control part 32 is cancelled, and the data transfer between the first and second memory 1, 2 can be started.