To provide an update method of firmware for easily updating the firmware without using any memory exclusive for the firmware, and for, when there is any problem in the new firmware, easily returning the new firmware to old firmware, and to provide a program and electronic equipment.

New firmware acquired from the outside is recorded in the continuous free clusters of a flash ROM in a state where firmware is recorded in the flash ROM beforehand. Thus, it is possible to easily update the firmware by changing the leading cluster of the memory area of the firmware. Also, when the update of the firmware fails, it is possible to return to the old firmware by returning the leading cluster of the memory area of the firmware to the original state. In any case, it is consequently possible to start electronic equipment, and to prevent the equipment from being operated.