A shunt type current sensor (1) using an infrared ray temperature detection unit as a temperature sensor (60) can detect the temperature of a shunt resistance portion (SR) directly through the detection of infrared rays radiated from the shunt resistance portion (SR). Such a detection method is not so much affected by thermal loss, as compared with a method for detecting a temperature in a course of sequential heat conduction via a bus bar (10) and a circuit board (20). It is therefore possible to suppress a gap between the temperature of the shunt resistance portion (SR) and the detected temperature.