A liquid phase diffusion bonding method for dissimilar metal sheets by allowing a galvanized steel sheet and an aluminum alloy sheet to come into close contact with each other and pressing both sheets by using a first mold of a liquid phase diffusion bonding apparatus and a second mold of the same; and heating the sheets at approximately the same heat-up rate and at approximately the same temperature to perform liquid phase diffusion bonding of the sheets by using induction heat generated by applying high frequency currents to a first high frequency induction heating coil provided on the first mold and a second high frequency induction heating coil provided on the second mold. The first high frequency induction heating coil and the second high frequency induction heating coil are positioned to sandwich the sheets at predetermined distances from the sheets, respectively.