A construction machine comprising: an electrical equipment (11,12) installed in a vehicle body (2,4); a communication terminal for transmitting information of the vehicle body (2,4) to a server; and a battery for supplying power to the electrical equipment (11,12) and the communication terminal, characterized in that: the construction machine further comprises: a plus-side main connection line for connecting the electrical equipment (11,12) and a plus terminal of the battery; a plus-side isolating switch provided on the plus-side main connection line for connecting or disconnecting the electrical equipment (11,12) to or from the plus terminal of the battery; a key switch positioned at a downstream side of the plus-side isolating switch and is connected in series to the plus-side isolating switch for connecting or disconnecting the electrical equipment (11,12) to or from the plus terminal of the battery; a plus-side auxiliary connection line positioned at an upstream side of the plus-side isolating switch for connecting the communication terminal and the plus terminal of the battery; a minus-side main connection line for connecting a minus terminal of the battery to ground; and a minus-side isolating switch provided on the minus-side main connection line for connecting or disconnecting the minus terminal of the battery to or from the ground. an electrical equipment (11,12) installed in a vehicle body (2,4); a communication terminal for transmitting information of the vehicle body (2,4) to a server; and a battery for supplying power to the electrical equipment (11,12) and the communication terminal, characterized in that: the construction machine further comprises: a plus-side main connection line for connecting the electrical equipment (11,12) and a plus terminal of the battery; a plus-side isolating switch provided on the plus-side main connection line for connecting or disconnecting the electrical equipment (11,12) to or from the plus terminal of the battery; a key switch positioned at a downstream side of the plus-side isolating switch and is connected in series to the plus-side isolating switch for connecting or disconnecting the electrical equipment (11,12) to or from the plus terminal of the battery; a plus-side auxiliary connection line positioned at an upstream side of the plus-side isolating switch for connecting the communication terminal and the plus terminal of the battery; a minus-side main connection line for connecting a minus terminal of the battery to ground; and a minus-side isolating switch provided on the minus-side main connection line for connecting or disconnecting the minus terminal of the battery to or from the ground. a plus-side main connection line for connecting the electrical equipment (11,12) and a plus terminal of the battery; a plus-side isolating switch provided on the plus-side main connection line for connecting or disconnecting the electrical equipment (11,12) to or from the plus terminal of the battery; a key switch positioned at a downstream side of the plus-side isolating switch and is connected in series to the plus-side isolating switch for connecting or disconnecting the electrical equipment (11,12) to or from the plus terminal of the battery; a plus-side auxiliary connection line positioned at an upstream side of the plus-side isolating switch for connecting the communication terminal and the plus terminal of the battery; a minus-side main connection line for connecting a minus terminal of the battery to ground; and a minus-side isolating switch provided on the minus-side main connection line for connecting or disconnecting the minus terminal of the battery to or from the ground.