The present invention addresses the problem of providing an impedance measuring device that enables a coupling capacitor to be charged in a short time period, and that enables a line break to be detected. This problem can be resolved by means of an impedance measuring device (200) comprising: a measuring unit (220) for obtaining an internal impedance of an object (230) being measured, by measuring a voltage generated between contact terminals that are respectively in contact with two terminals of the object (230) being measured, the voltage being generated by means of an alternating current supplied to the object (230) being measured; a line break detection current source (241) which supplies an alternating current for line break detection to an electric current path (201) between the measuring unit (220) and the object (230) being measured, via a coupling capacitor (C3); and a charge acceleration unit (242) which is connected between the coupling capacitor (C3) and the line break detection current source (241), and which charges the coupling capacitor (C3) if a terminal-to-terminal voltage of the line break detection current source (241) exceeds a prescribed voltage range.