A popped corn making apparatus used in a microwave oven comprises a bowl having an opening at the upper part and a narrow closed bottom and a substantially conical shape; and a resonator placed at the bottom of said bowl. The electric field resulted by resonance of said resonator under an application of microwave, is applied to grains of corn contained in said bowl to produce a popped corn.It is possible to use a lumped element resonator comprising a one turn coil having a ring shape having an opening which is placed at the bottom of said bowl and which is formed by an inductance provided by said coil and a capacitance provided by said bowl and said grains of corn.