NOVELTY - The inverter has capacitor circuits (41,42) connected so as to form neutral points (c,f) on input and output sides of single phase or three-phase inverting circuit (1). A common mode current bypass channel (g) is formed by connecting neutral points on capacitor circuits. A common mode choke coil unit is provided with common mode choke coils (31,32) between capacitor circuit and inverting circuit or between inverting circuit and another capacitor circuit, which uses inverting circuit to suppress generated common mode current.    USE - Grid connection inverter e.g. single-phase grid connection inverter and three-phase grid connection inverter for solar energy power generation system and fuel cell.    ADVANTAGE - The common mode electric current can be suppressed by using inverting circuit. Since the impedance of the common mode choke coils is larger than the impedance of the leakage current path and the bypass channel, the leakage currents can flow through a bypass channel with the low impedance and the magnitude of the leakage current can be suppressed with the choke coils. Thus the leakage current flowing out of the grid connection inverter and high frequency noise of the leakage current can be suppressed. The resonance occurred between the capacitor and the reactor of the output filter can be suppressed by setting the resistance value for the resistor. Since the reactor for supporting the output filter and the step up circuit is avoided, the size and the cost of the grid connection inverter can be reduced. Since the normal mode electric current hardly flow into the damping resistor, the loss generated in the damping resistor can be suppressed.    DETAILED DESCRIPTION - The inverting circuit changes direct current (DC) voltage supplied from DC power supply (5) to pulse-width modulated voltage. An output filter (2) converts pulse-width modulated voltage waveform output from inverter to sinusoidal single-phase or three-phase AC voltage.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit diagram of the grid connection inverter.    Inverting circuit (1)    Output filter (2)    DC power supply (5)    Grounded capacitor (11)    Common mode choke coils (31,32)    Capacitor circuits (41,42)    Neutral points (c,f)    Common mode current bypass channel (g)