A sensor configured so as to be capable of detecting a detected value for a covered wire without metallic contact, comprising: a support that is formed in a tubular shape, is provided with an insertion channel formed by cutting away part of a circumferential wall, and is capable of supporting the covered wire that has been inserted into the insertion channel; and a detection electrode that is formed in a pillar shape, characterized in that the sensor further comprises: a shell that is formed in a tubular shape and is capable of being inserted into the support from a base end side of the support; a male thread formed on an outer circumferential surface of the support; and a threaded piece that is formed in a tubular shape, has a female thread that screws onto the male thread formed on an inner circumferential surface thereof, is externally attached to the shell so as to be rotatable with respect to the shell, and is capable of being moved along a direction of an axis, which joins the base end and a front end of the support, together with the shell and the detection electrode that have been inserted into the support by a screwing operation that screws the female thread onto the male thread, and wherein the detection electrode is supported by the shell in a state where the detection electrode has been inserted inside the shell, and is inserted together with the shell into the support, the detection electrode being configured so that a front end surface thereof is capable of becoming capacitively coupled to a core wire of the covered wire via an insulating covering of the covered wire when the front end surface is pressed onto the covered wire that is supported on the support due to movement of the detection electrode toward a front end side of the support. a support that is formed in a tubular shape, is provided with an insertion channel formed by cutting away part of a circumferential wall, and is capable of supporting the covered wire that has been inserted into the insertion channel; and a detection electrode that is formed in a pillar shape, characterized in that the sensor further comprises: a shell that is formed in a tubular shape and is capable of being inserted into the support from a base end side of the support; a male thread formed on an outer circumferential surface of the support; and a threaded piece that is formed in a tubular shape, has a female thread that screws onto the male thread formed on an inner circumferential surface thereof, is externally attached to the shell so as to be rotatable with respect to the shell, and is capable of being moved along a direction of an axis, which joins the base end and a front end of the support, together with the shell and the detection electrode that have been inserted into the support by a screwing operation that screws the female thread onto the male thread, and wherein the detection electrode is supported by the shell in a state where the detection electrode has been inserted inside the shell, and is inserted together with the shell into the support, the detection electrode being configured so that a front end surface thereof is capable of becoming capacitively coupled to a core wire of the covered wire via an insulating covering of the covered wire when the front end surface is pressed onto the covered wire that is supported on the support due to movement of the detection electrode toward a front end side of the support. a shell that is formed in a tubular shape and is capable of being inserted into the support from a base end side of the support; a male thread formed on an outer circumferential surface of the support; and a threaded piece that is formed in a tubular shape, has a female thread that screws onto the male thread formed on an inner circumferential surface thereof, is externally attached to the shell so as to be rotatable with respect to the shell, and is capable of being moved along a direction of an axis, which joins the base end and a front end of the support, together with the shell and the detection electrode that have been inserted into the support by a screwing operation that screws the female thread onto the male thread, and wherein the detection electrode is supported by the shell in a state where the detection electrode has been inserted inside the shell, and is inserted together with the shell into the support, the detection electrode being configured so that a front end surface thereof is capable of becoming capacitively coupled to a core wire of the covered wire via an insulating covering of the covered wire when the front end surface is pressed onto the covered wire that is supported on the support due to movement of the detection electrode toward a front end side of the support.