A trimming element comprises (a) a medium layer, (b) a pair of electrodes connected to the medium layer, and (c) an alloy layer, which is formed of metal of the electrodes and material of the medium layer and is created in the medium layer, for substantially short-circuiting the electrodes to each other. The alloy layer is obtained by applying a laser beam to the medium layer to heat a portion between the electrodes. The metal layer for substantially short-circuiting the electrodes is thus formed.