A work machine which is controlled to be operated, based on communication with a remote operation apparatus, the work machine comprising: an actual machine power source; an actual machine switch which allows the work machine to be remotely operated by the remote operation apparatus; characterised by an actual machine control device comprising a switch terminal, a power source terminal and a ground terminal, the actual machine control device having a function of switching the ground terminal to be grounded or non-grounded in response to a command from the remote operation apparatus; a four-pin relay configured to cut off or connect between a pair of relay terminals in response to whether a pair of excitation terminals are energized; and a five-pin relay configured to connect between a reference relay terminal and a first relay terminal or connect between the reference relay terminal and a second relay terminal, in response to whether a pair of excitation terminals are energized, wherein the actual machine power source is connected to the switch terminal of the actual machine control device through the actual machine switch, connected to the power source terminal of the actual machine control device through the actual machine switch, and the reference relay terminal and the first relay terminal of the five-pin relay in order, connected to the power source terminal of the actual machine control device through the pair of relay terminals of the four-pin relay and a forward first diode in order. grounded through the pair of relay terminals of the four-pin relay, a forward second diode and the pair of excitation terminals of the five-pin relay in order, connected to the ground terminal of the actual machine control device through the pair of excitation terminals of the four-pin relay, and connected between the second diode and the five-pin relay through the actual machine switch, the reference relay terminal and the second relay terminal of the five-pin relay, and a forward third diode in order. an actual machine power source; an actual machine switch which allows the work machine to be remotely operated by the remote operation apparatus; characterised by an actual machine control device comprising a switch terminal, a power source terminal and a ground terminal, the actual machine control device having a function of switching the ground terminal to be grounded or non-grounded in response to a command from the remote operation apparatus; a four-pin relay configured to cut off or connect between a pair of relay terminals in response to whether a pair of excitation terminals are energized; and a five-pin relay configured to connect between a reference relay terminal and a first relay terminal or connect between the reference relay terminal and a second relay terminal, in response to whether a pair of excitation terminals are energized, wherein the actual machine power source is connected to the switch terminal of the actual machine control device through the actual machine switch, connected to the power source terminal of the actual machine control device through the actual machine switch, and the reference relay terminal and the first relay terminal of the five-pin relay in order, connected to the power source terminal of the actual machine control device through the pair of relay terminals of the four-pin relay and a forward first diode in order. grounded through the pair of relay terminals of the four-pin relay, a forward second diode and the pair of excitation terminals of the five-pin relay in order, connected to the ground terminal of the actual machine control device through the pair of excitation terminals of the four-pin relay, and connected between the second diode and the five-pin relay through the actual machine switch, the reference relay terminal and the second relay terminal of the five-pin relay, and a forward third diode in order. connected to the switch terminal of the actual machine control device through the actual machine switch, connected to the power source terminal of the actual machine control device through the actual machine switch, and the reference relay terminal and the first relay terminal of the five-pin relay in order, connected to the power source terminal of the actual machine control device through the pair of relay terminals of the four-pin relay and a forward first diode in order. grounded through the pair of relay terminals of the four-pin relay, a forward second diode and the pair of excitation terminals of the five-pin relay in order, connected to the ground terminal of the actual machine control device through the pair of excitation terminals of the four-pin relay, and connected between the second diode and the five-pin relay through the actual machine switch, the reference relay terminal and the second relay terminal of the five-pin relay, and a forward third diode in order.