To provide a current detection circuit and a protection circuit capable of carrying out a current detection in consideration of temperature characteristics, which are of current detection circuits and protection circuits for converting input current into voltage by using a current-voltage converting element, comparing the converted voltage with a reference voltage, and outputting an output signal in accordance with the resultant magnitude relation.

The current detection circuit (11) has a current-voltage converting element (RS) which generates a voltage in accordance with its input current; a reference voltage generating circuit (41) which generates a reference voltage (Vref); and a comparator (42) which outputs an output signal in accordance with the magnitude relation between the voltage (Vs) obtained by the current-voltage converting element (RS) and the reference voltage (Vref) generated by the reference voltage generating circuit (41). The reference voltage generating circuit (41) is configured to be set by a element structure which provides the reference voltage (Vref) with a temperature characteristic being previously set.