A pressure detection apparatus has a pressure-sensitive resistor whose first resistance varies according to pressure and a change of its own temperature, a temperature-sensitive resistor which has a same resistance-temperature coefficient as the pressure-sensitive resistor and whose second resistance varies according to the change of the temperature, a current source supplying first and second constant-currents to the pressure-sensitive and temperature-sensitive resistors respectively, and a pressure signal generation output section. The current source adjusts the first and second constant-currents so that when the pressure is an initial pressure, a reference first voltage appearing across the pressure-sensitive resistor and a reference second voltage appearing across the temperature-sensitive resistor become equal to each other. The pressure signal generation output section outputs a first voltage signal corresponding to the pressure on the basis of a difference voltage between a first voltage of the pressure-sensitive resistor and a second voltage of the temperature-sensitive resistor.