A communication apparatus includes: a controller that controls processing to perform facsimile; a first controlling unit that controls a voltage between lines that perform facsimile in accordance with control by the controller; a detector that detects a voltage change between the lines; and second controlling unit that discharges electric charge accumulated in between the lines so as to enable the detector to detect a voltage change between the lines when the first controlling unit is turned off. The controller determining whether connection to the lines is made based on the voltage change detected by detector.