PURPOSE: To perform staking readily and evely by supplying current to the members to be staked to caue them to make plastic deformation while being softened thereby performing staking.

CONSTITUTION: The 1st member to be coupled 1 is superposed on the bottom surface of the 2nd member to be coupled 2 by passing its protruding part 1a into the through-hole 2a. An upper electrode 3 is lowered to hole the protruding part 1a between the electrodes 3, 4 and the current of the specified value is supplied for the specified time to the protruding part 1a, at the same instant of which the specified pressure is applied to stake the protruding part 1a. At this time, the protruding part 1a is heated by current to soften and is plastically deformed by pressing force, whereby the staking is accomplished.