An overcurrent detection device comprising: a current detection resistor that is connected in series to a main circuit and is configured to cause a potential difference at both ends according to a current flowing through the main circuit; a current detection circuit that includes a pair of connection portions and is configured to detect a potential difference between said pair of connection portions; and a pair of voltage detection lines, each voltage detection line connecting a respective end of the current detection resistor to a respective connection portion in the current detection circuit for inputting the potential difference between the both ends of the current detection resistor into the pair of connection portions of the current detection circuit; characterized by an erroneous detection prevention unit configured to prevent an increase in the potential difference between the pair of connection portions to or above a value corresponding to an overcurrent detection threshold value, when at least any one of the pair of voltage detection lines has a disconnection or connection failure; wherein the erroneous detection prevention unit comprises a resistance element that is directly connected in parallel to one of or between the pair of connection portions in the current detection circuit, the resistance element having higher resistance than the current detection resistor and such that, in a case where a disconnection or a connection failure occurs in the voltage detection line connected to the respective connection portion and resistance element, the potential difference between the pair of connection portions of the current detection circuit is reduced to a predetermined value or less by the resistance element. a current detection resistor that is connected in series to a main circuit and is configured to cause a potential difference at both ends according to a current flowing through the main circuit; a current detection circuit that includes a pair of connection portions and is configured to detect a potential difference between said pair of connection portions; and a pair of voltage detection lines, each voltage detection line connecting a respective end of the current detection resistor to a respective connection portion in the current detection circuit for inputting the potential difference between the both ends of the current detection resistor into the pair of connection portions of the current detection circuit; characterized by an erroneous detection prevention unit configured to prevent an increase in the potential difference between the pair of connection portions to or above a value corresponding to an overcurrent detection threshold value, when at least any one of the pair of voltage detection lines has a disconnection or connection failure; wherein the erroneous detection prevention unit comprises a resistance element that is directly connected in parallel to one of or between the pair of connection portions in the current detection circuit, the resistance element having higher resistance than the current detection resistor and such that, in a case where a disconnection or a connection failure occurs in the voltage detection line connected to the respective connection portion and resistance element, the potential difference between the pair of connection portions of the current detection circuit is reduced to a predetermined value or less by the resistance element.