A pressure detection device comprising: a pressure detection element which receives pressure so as to output a detection signal (Qi) corresponding to the pressure; and a processing circuit (50, 70) which processes and outputs the detection signal (Qi) output from the pressure detection element, wherein the processing circuit (50, 70) includes: an integrator circuit (51, 71) which uses a reference voltage (Vr) set to have a predetermined magnitude as an operation reference and integrates the detection signal (Qi) so as to convert the detection signal into a voltage waveform; at least one or more amplifier circuits (52, 72, 73) which use a reference voltage (Vr) set to have a predetermined magnitude as an operation reference and amplify an output signal (Vout21, Vout31) from the integrator circuit; and a base voltage adjustment circuit which is connected between a supply portion of the reference voltage (Vr) fed to the amplifier circuit (52, 72, 73) and an input terminal of at least one of the amplifier circuits and which adjusts a magnitude of a base voltage (Vb22, Vb33) that is a potential when the detection signal in the output signal (Vout22, Vout33) output from the amplifier circuit is not present, characterised in that the base voltage adjustment circuit is formed of a transistor pair in which the emitter of a pnp transistor is connected to the base of an npn transistor. a pressure detection element which receives pressure so as to output a detection signal (Qi) corresponding to the pressure; and a processing circuit (50, 70) which processes and outputs the detection signal (Qi) output from the pressure detection element, wherein the processing circuit (50, 70) includes: an integrator circuit (51, 71) which uses a reference voltage (Vr) set to have a predetermined magnitude as an operation reference and integrates the detection signal (Qi) so as to convert the detection signal into a voltage waveform; at least one or more amplifier circuits (52, 72, 73) which use a reference voltage (Vr) set to have a predetermined magnitude as an operation reference and amplify an output signal (Vout21, Vout31) from the integrator circuit; and a base voltage adjustment circuit which is connected between a supply portion of the reference voltage (Vr) fed to the amplifier circuit (52, 72, 73) and an input terminal of at least one of the amplifier circuits and which adjusts a magnitude of a base voltage (Vb22, Vb33) that is a potential when the detection signal in the output signal (Vout22, Vout33) output from the amplifier circuit is not present, characterised in that the base voltage adjustment circuit is formed of a transistor pair in which the emitter of a pnp transistor is connected to the base of an npn transistor. an integrator circuit (51, 71) which uses a reference voltage (Vr) set to have a predetermined magnitude as an operation reference and integrates the detection signal (Qi) so as to convert the detection signal into a voltage waveform; at least one or more amplifier circuits (52, 72, 73) which use a reference voltage (Vr) set to have a predetermined magnitude as an operation reference and amplify an output signal (Vout21, Vout31) from the integrator circuit; and a base voltage adjustment circuit which is connected between a supply portion of the reference voltage (Vr) fed to the amplifier circuit (52, 72, 73) and an input terminal of at least one of the amplifier circuits and which adjusts a magnitude of a base voltage (Vb22, Vb33) that is a potential when the detection signal in the output signal (Vout22, Vout33) output from the amplifier circuit is not present, characterised in that the base voltage adjustment circuit is formed of a transistor pair in which the emitter of a pnp transistor is connected to the base of an npn transistor.