In a semiconductor physical quantity sensor of electrostatic capacitance type, mutually facing peripheral areas of a glass substrate and a silicon substrate are contacted for anodic bonding, while at the same time, both substrates have an anodic bonding voltage applied therebetween so as to be integrated. Dither is summed with an input signal to an ADC by passing a serial pseudo-random bitstream through an analog filter. A p-type silicon carbide well region is provided on the n\u2212 silicon carbide layer.