A single-phase photovoltaic inverter, configured to convert direct current electric power supplied from a single-phase photovoltaic module into alternating current electric power, and comprising: an input terminal including a first input terminal connected to a positive polarity of the single-phase photovoltaic module and a second input terminal connected to a negative polarity of the single-phase photovoltaic module; an inverter unit configured to convert direct current electric power supplied through the input terminal into alternating current electric power and supply the converted alternating current electric power to a grid; and a leakage current measuring unit connected in parallel to the inverter unit and configured to measure a leakage current delivered through the input terminal, characterized in that the leakage current measuring unit further comprises: a first insulated transformer having one end connected to the first input terminal, and configured to amplify a leakage current flowing to a ground; a first current transformer having one end connected to the other end of the first insulated transformer and the other end connected to the ground, and configured to measure the leakage current amplified by the first insulated transformer; a second insulated transformer having one end connected to the second input terminal, and configured to amplify the leakage current flowing to the ground; a second current transformer having one end connected to the other end of the second insulated transformer and the other end connected to the 5 ground, and configured to measure the leakage current amplified by the second insulated transformer; a first sensing line configured to deliver the leakage current measured by the first current transformer to a controller; and a second sensing line configured to deliver the leakage current measured by the second current transformer to the controller, wherein the first current transformer and the second current transformer are disposed on a side of the first insulated transformer and the second insulated transformer where a high voltage is formed due to the amplified leakage current, respectively. an input terminal including a first input terminal connected to a positive polarity of the single-phase photovoltaic module and a second input terminal connected to a negative polarity of the single-phase photovoltaic module; an inverter unit configured to convert direct current electric power supplied through the input terminal into alternating current electric power and supply the converted alternating current electric power to a grid; and a leakage current measuring unit connected in parallel to the inverter unit and configured to measure a leakage current delivered through the input terminal, characterized in that the leakage current measuring unit further comprises: a first insulated transformer having one end connected to the first input terminal, and configured to amplify a leakage current flowing to a ground; a first current transformer having one end connected to the other end of the first insulated transformer and the other end connected to the ground, and configured to measure the leakage current amplified by the first insulated transformer; a second insulated transformer having one end connected to the second input terminal, and configured to amplify the leakage current flowing to the ground; a second current transformer having one end connected to the other end of the second insulated transformer and the other end connected to the 5 ground, and configured to measure the leakage current amplified by the second insulated transformer; a first sensing line configured to deliver the leakage current measured by the first current transformer to a controller; and a second sensing line configured to deliver the leakage current measured by the second current transformer to the controller, a first insulated transformer having one end connected to the first input terminal, and configured to amplify a leakage current flowing to a ground; a first current transformer having one end connected to the other end of the first insulated transformer and the other end connected to the ground, and configured to measure the leakage current amplified by the first insulated transformer; a second insulated transformer having one end connected to the second input terminal, and configured to amplify the leakage current flowing to the ground; a second current transformer having one end connected to the other end of the second insulated transformer and the other end connected to the 5 ground, and configured to measure the leakage current amplified by the second insulated transformer; a first sensing line configured to deliver the leakage current measured by the first current transformer to a controller; and a second sensing line configured to deliver the leakage current measured by the second current transformer to the controller, wherein the first current transformer and the second current transformer are disposed on a side of the first insulated transformer and the second insulated transformer where a high voltage is formed due to the amplified leakage current, respectively.