A semiconductor element comprises a capacitance variable section and an inductor section. In the capacitance variable section, a variable capacitance diode equipped with first and second control electrodes is provided on an insulative substrate. The inductor section is formed on the capacitance variable section formed with the variable capacitance diode. The inductor section is formed in an insulating layer provided on the variable capacitance diode. A first input/output electrode, a second input/output electrode, and first and second control input/output electrodes are provided in exposed form on the upper side of the insulating layer provided on the capacitance variable section. Further, a turbinated spiral electrode that electrically connects the first input/output electrode and the second input/output electrode, a first control lead-out electrode that electrically connects between the first control electrode and the first control input/output electrode, and a second control lead-out electrode that electrically connects between the second control electrode and each second control input/output electrode, are provided within the insulating layer.