PROBLEM TO BE SOLVED: To provide a low-cost injection apparatus not including pressure detection means, and to easily obtain an injection pressure of a liquid medicine with high accuracy without using the pressure detection means, in the injection apparatus operating by use of an ultrasonic motor.SOLUTION: An injection apparatus 1 for injecting a liquid medicine includes: an ultrasonic motor 3 a drive mechanism 4 driven by the ultrasonic motor 3 so as to send out the liquid medicine current value measurement means 506 measuring a current value of current supplied to the ultrasonic motor 3 and a controller 5 controlling the ultrasonic motor 3. The controller 5 obtains an injection pressure on the basis of the measured current value by use of a data table in which the injection pressure of the liquid medicine is set in each current value, and controls the ultrasonic motor 3 such that the obtained injection pressure does not exceed an injection pressure limit value.
