A current mirror circuit has a first MOS transistor to which an input current is supplied. The first MOS transistor has a gate formed of polysilicon. A second MOS transistor has a gate formed of polysilicon and connected directly to the gate of the first MOS transistor via a polysilicon layer for producing an output current whose magnitude is a magnitude of the input current multiplied by a current mirror ratio. A fuse has one terminal connected to a gate portion between the gate of the first MOS transistor and the gate of the second MOS transistor and another terminal that is grounded.