The purpose of the present invention is to inhibit, in a simpler manner, the theft of a battery pack capable of being attached to and detached from a portable electric work machine. An electric brush cutter 1 is provided with: a battery pack 200 capable of assuming either a sleep state or an active state; and a work-machine main body 100. The battery pack 200 is provided with a memory 230 having, stored therein, information indicating the state of a battery 210. The brush cutting work-machine main body 100 is provided with: a work unit 130; and a work-machine controller 111 for controlling the work unit 130. The work-machine controller 111 prohibits operation of the work unit 130 when the information stored in the memory 230 of the battery pack indicates the sleep state, and enables operation of the work unit 130 when the information stored in the memory 230 of the battery pack indicates the active state.
