An inverter (1a, 1b, 1c) comprising a power source circuit configured to carry out electric power delivery to a control target device; a processor including a communication circuit configured to carry out communication with a master device via a network, and an electric power delivery control circuit configured to control electric power delivery to the power source circuit; and a power supply configured to carry out electric power delivery to the processor (20a, 20b, 20c) and to the power source circuit; characterized in that the electric power delivery control circuit is configured to block the electric power delivery to the power source circuit in a case where the inverter (1a, 1b, 1c) is to enter a standby state, which is a state in which the inverter (1a, 1b, 1c) does not control the control target device, the communication circuit is configured to receive, from the master device, a driving command which is an instruction for driving the inverter (1a, 1b, 1c) or a motor connected to the inverter, in a case where the communication circuit has not received the driving command for a certain period of time, the electric power delivery control circuit blocks the electric power delivery to the power source circuit, the driving command contains information indicating a frequency of an output current to the motor, and in a case where the frequency indicated by the driving command is 0, the electric power delivery control circuit blocks the electric power delivery to the power source circuit. a power source circuit configured to carry out electric power delivery to a control target device; a processor including a communication circuit configured to carry out communication with a master device via a network, and an electric power delivery control circuit configured to control electric power delivery to the power source circuit; and a communication circuit configured to carry out communication with a master device via a network, and an electric power delivery control circuit configured to control electric power delivery to the power source circuit; and a power supply configured to carry out electric power delivery to the processor (20a, 20b, 20c) and to the power source circuit; characterized in that the electric power delivery control circuit is configured to block the electric power delivery to the power source circuit in a case where the inverter (1a, 1b, 1c) is to enter a standby state, which is a state in which the inverter (1a, 1b, 1c) does not control the control target device, the communication circuit is configured to receive, from the master device, a driving command which is an instruction for driving the inverter (1a, 1b, 1c) or a motor connected to the inverter, in a case where the communication circuit has not received the driving command for a certain period of time, the electric power delivery control circuit blocks the electric power delivery to the power source circuit, the driving command contains information indicating a frequency of an output current to the motor, and in a case where the frequency indicated by the driving command is 0, the electric power delivery control circuit blocks the electric power delivery to the power source circuit.