Direct methanol fuel cell liquid fuel with water and methanol having specific electrical resistance and direct methanol fuel cell cartridge

5 7 A direct methanol fuel cell liquid fuel including methanol and water to be supplied to an anode of a direct methanol fuel cell, in which an electrical resistance of the liquid fuel is 5×10Ω·cm or more and 1×10Ω·m or less at 25° C. A direct methanol fuel cell cartridge storing the direct methanol fuel cell liquid fuel, and a direct methanol fuel cell system. Such structures can provide a direct methanol fuel cell liquid fuel, a direct methanol fuel cell cartridge, and a direct methanol fuel cell system all appropriately used for stable electricity generation over a long period of time.