A magnetic permeability detector comprising: an LC oscillator circuit including a coil and a capacitor ; and a resistor connected in series with the coil , wherein: the resistor adds a predetermined resistance value to a circuit resistance value of the LC oscillator circuit , an oscillation frequency of the LC oscillator circuit being dependent on the circuit resistance value and the predetermined resistance value, wherein the resistor functions as a resistance adjuster that does not affect inductance of the coil even when the predetermined resistance value of the resistor is changed; the coil generates a magnetic flux in a predetermined direction by a current flowing through the coil upon application of a power supply voltage to the magnetic permeability detector , the magnetic permeability detector further comprises an output terminal to output a signal having a frequency corresponding to a magnetic permeability in a range of action of the magnetic flux; and the predetermined resistance value of the resistor makes a temperature characteristic of the frequency of the signal output from the output terminal closer to a temperature characteristic of a reference clock based on which the signal output from the output terminal is counted. an LC oscillator circuit including a coil and a capacitor ; and a resistor connected in series with the coil , wherein: the resistor adds a predetermined resistance value to a circuit resistance value of the LC oscillator circuit , an oscillation frequency of the LC oscillator circuit being dependent on the circuit resistance value and the predetermined resistance value, wherein the resistor functions as a resistance adjuster that does not affect inductance of the coil even when the predetermined resistance value of the resistor is changed; the coil generates a magnetic flux in a predetermined direction by a current flowing through the coil upon application of a power supply voltage to the magnetic permeability detector , the magnetic permeability detector further comprises an output terminal to output a signal having a frequency corresponding to a magnetic permeability in a range of action of the magnetic flux; and the predetermined resistance value of the resistor makes a temperature characteristic of the frequency of the signal output from the output terminal closer to a temperature characteristic of a reference clock based on which the signal output from the output terminal is counted. the resistor adds a predetermined resistance value to a circuit resistance value of the LC oscillator circuit , an oscillation frequency of the LC oscillator circuit being dependent on the circuit resistance value and the predetermined resistance value, wherein the resistor functions as a resistance adjuster that does not affect inductance of the coil even when the predetermined resistance value of the resistor is changed; the coil generates a magnetic flux in a predetermined direction by a current flowing through the coil upon application of a power supply voltage to the magnetic permeability detector , the magnetic permeability detector further comprises an output terminal to output a signal having a frequency corresponding to a magnetic permeability in a range of action of the magnetic flux; and the predetermined resistance value of the resistor makes a temperature characteristic of the frequency of the signal output from the output terminal closer to a temperature characteristic of a reference clock based on which the signal output from the output terminal is counted. <EOS>