A method for managing main memory including DRAM and NVRAM in a computer depending on the operation state of the computer is provided. The method includes: (a) upon start of the computer, loading a program and the like into the DRAM, and loading predetermined read-only data and the like into the NVRAM; (b) in a state transition from a normal operation to a suspend state, moving data in the DRAM to the NVRAM; (c) in a state transition from the suspend state to the normal operation, reading data from the NVRAM for program execution; (d) in the case where a data write to the NVRAM occurs, stopping the data write, and moving data in a data area of the NVRAM subjected to the data write, to the DRAM; and (e) performing the data write to the DRAM to which the data has been moved.