An inverter structure for a vehicle is provided. The inverter includes a capacitor for receiving direct current supplied from a battery, a power module assembly including a plurality of power modules and a plurality of coolers, and an output bus-bar connected to the plurality of power modules to output three-phase alternating current to a motor. In particular, inside of the power module, power modules of a plurality of power modules are connected to the capacitor to convert the direct current into the three-phase alternating current, and coolers of a plurality of coolers are alternately stacked one above another such that each cooler comes into contact at its upper and lower surfaces with adjacent power modules to enable heat transfer.