An ion current measurement apparatus comprising a detection section and a control section: the detection section including first and second conductors (2, 3) and a substrate which is formed of ceramic and in which the first and second conductors (2, 3) are separately embedded and held, the detection section being adapted for attachment to an internal combustion engine such that the substrate is exposed to a combustion chamber of the internal combustion engine in which ions are generated as a result of combustion of fuel; and the first conductor being a heating element which generates heat when electricity is supplied thereto; the control section comprising: a measurement section (52, S610, S620) which measures a value of current (lion) flowing through the second conductor as an ion current originating from the generated ions, characterised in that the control section comprises: an obtainment section adapted to obtain an electrical resistance (R 11) of the substrate between the first conductor and the second conductor based on a potential difference between the first conductor and the second conductor and an electrical current flowing between the first conductor and the second conductor; and an energization controller which controls the supply of electricity to the first conductor such that the electrical resistance (R 11) obtained by the obtainment section becomes equal to a predetermined value, wherein the measurement section measures the current value (lion) in a case in which the electrical resistance (R 11) obtained by the obtainment section is within a predetermined range in a state in which the supply of electricity to the first conductor is controlled by the energization controller. the detection section including first and second conductors (2, 3) and a substrate which is formed of ceramic and in which the first and second conductors (2, 3) are separately embedded and held, the detection section being adapted for attachment to an internal combustion engine such that the substrate is exposed to a combustion chamber of the internal combustion engine in which ions are generated as a result of combustion of fuel; and the first conductor being a heating element which generates heat when electricity is supplied thereto; the control section comprising: a measurement section (52, S610, S620) which measures a value of current (lion) flowing through the second conductor as an ion current originating from the generated ions, characterised in that the control section comprises: an obtainment section adapted to obtain an electrical resistance (R 11) of the substrate between the first conductor and the second conductor based on a potential difference between the first conductor and the second conductor and an electrical current flowing between the first conductor and the second conductor; and an energization controller which controls the supply of electricity to the first conductor such that the electrical resistance (R 11) obtained by the obtainment section becomes equal to a predetermined value, wherein the measurement section measures the current value (lion) in a case in which the electrical resistance (R 11) obtained by the obtainment section is within a predetermined range in a state in which the supply of electricity to the first conductor is controlled by the energization controller. a measurement section (52, S610, S620) which measures a value of current (lion) flowing through the second conductor as an ion current originating from the generated ions, characterised in that the control section comprises: an obtainment section adapted to obtain an electrical resistance (R 11) of the substrate between the first conductor and the second conductor based on a potential difference between the first conductor and the second conductor and an electrical current flowing between the first conductor and the second conductor; and an energization controller which controls the supply of electricity to the first conductor such that the electrical resistance (R 11) obtained by the obtainment section becomes equal to a predetermined value, an obtainment section adapted to obtain an electrical resistance (R 11) of the substrate between the first conductor and the second conductor based on a potential difference between the first conductor and the second conductor and an electrical current flowing between the first conductor and the second conductor; and an energization controller which controls the supply of electricity to the first conductor such that the electrical resistance (R 11) obtained by the obtainment section becomes equal to a predetermined value, wherein the measurement section measures the current value (lion) in a case in which the electrical resistance (R 11) obtained by the obtainment section is within a predetermined range in a state in which the supply of electricity to the first conductor is controlled by the energization controller.