A pressure detection device includes: a piezoelectric element that detects a pressure change via a diaphragm head or the like; a circuit board that is provided with a processing circuit that performs electrical processing with respect to a charge signal outputted from the piezoelectric element; a conductive housing member, which has conductivity and is disposed to cover (house) the circuit board, and which is connected to the ground of the circuit board; and a housing (a leading end side housing, the diaphragm head and a rear end side housing), which houses the piezoelectric element, the circuit board and the housing member, and which is electrically insulated from the piezoelectric element, the circuit board and the housing member.