Positioner

According to the invention, it is quite easy to adjust a positioner when the positioner is installed to an adjusting valve. The provided positioner (100) is characterized in that the positioner comprises an electrical-air conversion part (100), a valve shaft position detection part (17), a control signal generation part (20) and a valve opening position data generation part (21); the electrical-air conversion part converts an electrical signal indicating the valve opening of the adjusting valve into an air signal and supplies the air signal to an operator of the adjusting valve so as to operate a valve shaft of the adjusting valve; the valve shaft position detection part detects the position of the valve shaft of the adjusting valve; the control signal generation part generates an electrical signal according to the valve opening target value of the adjusting valve and the position of the valve shaft of the adjusting valve detected by the valve shaft position detection part; and the valve opening position data