PURPOSE: To provide a motor controller for an electric vehicle having a small size and excellent assembling properties.

CONSTITUTION: The motor controller for an electric vehicle comprises a frame 53, cooling blocks 56-58 fixed to be stood in the frame 53 to dissipate heat via cooling medium, a current control element arranged in contact with both surfaces of the blocks 56-58 to form a waveform of an AC current upon reception of a switching signal, and at least a pair of boards 61 stood to hold the blocks 56-58 and the element. A plurality of elements for preventing generation of an overvoltage when the element is turned OFF are mounted on the board 61, and a smoothing capacitor C1 for smoothing a voltage waveform of a power source side is mounted between the paired boards 61. Since heat dissipating quantity is increased, the blocks 56-58 can be reduced, and a snubber circuit and the capacitor C1 can be arranged, and hence special wirings are not required.