Provided is an inverter device that can reduce high-frequency noise. The inverter device includes a transformer for converting the voltage of the AC power output from an inverter circuit and outputting the resulting power. Each of first to third coil sections for converting the voltage of the AC power output from the inverter circuit and outputting the resulting power includes an inner coil respectively wound around first to third core sections and an outer coil. The first to third core sections are each column shaped having an axis in the Y direction, and are arranged in the Z direction. Non-magnetic pressing members are provided between the adjacent coil sections and between the adjacent coil sections. The pressing members press against the adjacent coil sections and the adjacent coil sections respectively.