CURRENT SENSOR

The current sensor includes a battery terminal part that has electrical conductivity and is fastened to a battery post constituting a negative electrode of a battery, and a shunt resistor that is conductively connected to the battery terminal part via a joint part, the shunt resistor including a first detection terminal and a second detection terminal for detecting an electric current. The battery terminal part includes a third detection terminal for detecting a voltage of the battery between the joint part and the battery post. As a result, the current sensor can properly detect a voltage of the battery together with an electric current.