[Problem] To provide a current sensor having a structure in which a magnetic sensor is less likely to be saturated. [Solution] This current sensor 1 comprises: a bus bar 10 through which a current I to be measured flows; and a magnetic sensor 20 which detects a magnetic field generated by a current flowing through the bus bar 10. The bus bar 10 includes a sensing portion 13A, a dome-shaped bypass portion 11 that covers the sensing portion from a +y direction, and a dome-shaped bypass portion 12 that covers the sensing portion 13A from a −y direction, and the magnetic sensor 20 is disposed in a surrounding space surrounded by bypass portions 11, 12. In this way, since the magnetic sensor 20 is disposed in the surrounding space where the magnetic field is zero, the magnetic sensor 20 can perform correct measurement without being saturated even when the current flowing through the bus bar 10 is a large current. Moreover, since the bypass portions 11, 12 are dome-shaped, the size of the bus bar 10 in a z direction can be shortened.