A memory controller for preventing the storage area of a flash memory being reduced is provided. The memory controller controlling access to a flash memory based on a command provided from a host system, the memory controller includes: a processor, a RAM (random access memory), and a mask ROM (read only memory) in which a first firmware is written, wherein the memory controller is configured to: perform a search for a second firmware written in the flash memory based on the first firmware at a start-up time; and write a third firmware provided from the host system in the RAM when the second firmware is not found through the search and perform an initialization based on the third firmware written in the RAM.