An input apparatus comprising: a switch that switches an input mode as a result of an operation knob, which is attached to a case, being operated; and an electrostatic capacitance sensor that detects an operating body coming close to or being in contact with the operation knob, wherein the electrostatic capacitance sensor includes an electrostatic-capacitance detection plate attached to a rear surface of the operation knob, the electrostatic-capacitance detection plate being made of a metal, a circuit board disposed in such a manner as to face the operation knob with a predetermined distance between the circuit board and the operation knob, an electrostatic capacitance detection circuit pattern formed on the circuit board, and a compression-coil spring having a first end, which is caused to abut against the electrostatic-capacitance detection plate by an urging force in such a manner as to be electrically connected to the electrostatic-capacitance detection plate, and a second end, which is caused to abut against the electrostatic capacitance detection circuit pattern by an urging force so as to be electrically connected to the electrostatic capacitance detection circuit pattern, wherein a spring support member is provided on a side on which the rear surface of the operation knob is present, a spring support hole into which the compression-coil spring is inserted is formed in the spring support member in such a manner as to extend through the spring support member, characterised in that the spring support hole is formed such that a width of the spring support hole on an entry side from which the compression-coil spring is inserted is larger than the width of the spring support hole on an exit side from which the compression-coil spring is exited, and that a portion of the compression-coil spring on the first end side is supported in such a manner as to be capable of freely reciprocating on the exit side of the spring support hole. a switch that switches an input mode as a result of an operation knob, which is attached to a case, being operated; and an electrostatic capacitance sensor that detects an operating body coming close to or being in contact with the operation knob, wherein the electrostatic capacitance sensor includes an electrostatic-capacitance detection plate attached to a rear surface of the operation knob, the electrostatic-capacitance detection plate being made of a metal, a circuit board disposed in such a manner as to face the operation knob with a predetermined distance between the circuit board and the operation knob, an electrostatic capacitance detection circuit pattern formed on the circuit board, and a compression-coil spring having a first end, which is caused to abut against the electrostatic-capacitance detection plate by an urging force in such a manner as to be electrically connected to the electrostatic-capacitance detection plate, and a second end, which is caused to abut against the electrostatic capacitance detection circuit pattern by an urging force so as to be electrically connected to the electrostatic capacitance detection circuit pattern, wherein an electrostatic-capacitance detection plate attached to a rear surface of the operation knob, the electrostatic-capacitance detection plate being made of a metal, a circuit board disposed in such a manner as to face the operation knob with a predetermined distance between the circuit board and the operation knob, an electrostatic capacitance detection circuit pattern formed on the circuit board, and a compression-coil spring having a first end, which is caused to abut against the electrostatic-capacitance detection plate by an urging force in such a manner as to be electrically connected to the electrostatic-capacitance detection plate, and a second end, which is caused to abut against the electrostatic capacitance detection circuit pattern by an urging force so as to be electrically connected to the electrostatic capacitance detection circuit pattern, wherein a spring support member is provided on a side on which the rear surface of the operation knob is present, a spring support hole into which the compression-coil spring is inserted is formed in the spring support member in such a manner as to extend through the spring support member, characterised in that the spring support hole is formed such that a width of the spring support hole on an entry side from which the compression-coil spring is inserted is larger than the width of the spring support hole on an exit side from which the compression-coil spring is exited, and that a portion of the compression-coil spring on the first end side is supported in such a manner as to be capable of freely reciprocating on the exit side of the spring support hole.