PURPOSE: To obtain a controller for an electric railcar in which high adhesion can be obtained without sensing idle slide and a variation in a torque can be suppressed to a small value.

CONSTITUTION: A torque command from a torque pattern generator 1 is supplied to a current pattern generator 2 and a frequency pattern generator 3. A current command, a slid frequency command is supplied from the generators 2, 3 to an inverter controller 4, which supplies a control signal to an inverter 5, thereby driving an induction motor 7. A signal S2 representing a slip frequency fs from the controller 4 and a signal S1 representing a reference slip frequency fsr from the generator 3 are supplied to subtracter 9, and a signal S5 representing a deviation Δfs from the subtracter 9 is supplied to an adhesion degree inference unit 10. The unit 10 infers an adhesion degree by fuzzy inference based on the deviation Δfs. An adhesion degree signal to be output from the unit 10 is supplied to the generator 1 to continuously correct a torque command.