Abstract: A capacitor test apparatus for checking the capacitance of a capacitor without removing the capacitor from the circuit. Selection of the designated capacitance of the capacitor by means of a user-actuated selector switch automatically selects a test signal frequency such that the reactance of the capacitor matches a reference impedance. A indicator circuit compares the actual reactance with the reference impedance to indicate the deviation of the test capacitor from its designated capacitance. The test signal is a low level sine wave which does not exceed the conduction threshold of semiconductor junctions associated with the capacitor. A user-actuated switch is provided for discharging any charge present on the capacitor prior to testing.