Electric Power Tool, and Program

An electric power tool (1) includes a tool element (5), an electric motor (10), a rechargeable battery (20), a fuel battery (30), a state measuring unit (22, 24, 401, S100, S125), and a control unit (40). The electric motor (10) receives power supply to drive the tool element (5). The rechargeable battery (20) is electrically connected to the electric motor (10) and supplies power to the electric motor (10). The fuel battery (30) is electrically connected to the rechargeable battery (20) and charges the rechargeable battery (20). The state measuring unit (22, 24, 401, S100, S125) measures a state of the rechargeable battery (20). The control unit (40) controls charging of the rechargeable battery (20) by the fuel battery (30) at least based on the state of the rechargeable battery (20) measured by the state measuring unit (22, 24, 401, S100, S125).