To provide a method for forming a plated film while keeping the internal stress of the plated film at a predetermined value.

This electrocasting method includes: electrocasting an article to be treated with nickel while simultaneously feeding currents having current densities of 1 A/dm2, 5 A/dm2, and 10 A/dm2 respectively to three pairs of a cathode and an anode in a preparation tank 20; after a lapse of 100 seconds, calculating the internal stress of the plated film with a strain measuring instrument 23 based on a strain quantity measured by a strain gauge 24; and outputting the calculated result to a computer 25. The computer 25 determines a current density at which the internal stress of the plated film is zero by using a table, and outputs a signal corresponding to the determined current density to a rectifier 15. The method also includes starting nickel-electrocasting by feeding the current having the current density at which the internal stress of the plated film is zero to the cathode and the anode in a main tank 10.