A semiconductor device 3 for sensing a physical quantity adjusts the output characteristic of a pressure sensor, for example, based on trimming data stored in an EPROM 34. A comparator 311 compares an input voltage given to a terminal 43 and a predetermined reference voltage, and delivers a write control signal for EPROM 34. When the comparator 311 delivers a Low signal for the EPROM 34, a first gate circuit 312 provided between the terminal 43 and a temperature sensor 32 connects the terminal 43 and the temperature sensor 32. A second gate circuit 313 provided between the terminal 43 and a pull-down resistor 314 disconnects the terminal 43 and the pull-down resistor 314. The operational voltage of the temperature sensor 32 is lower than the reference voltage, and the terminal 43 is used as an output terminal for the temperature sensor 32.