A receiving device includes: an antenna to which a communication signal containing time information is inputted; a ground allowing the antenna to function; a conductive part; a gain characteristics change unit which interrupts continuity between the ground and the conductive part to change the gain characteristics of the antenna; a receiving unit which obtains the time information from the communication signal inputted to the antenna; and a control unit which commands the gain characteristics change unit to interrupt the continuity and commands the receiving unit to obtain the time information. When the time information cannot be obtained from the communication signal inputted to the antenna having a certain type of gain characteristics, the control unit commands the gain characteristics change unit to interrupt the continuity and commands the receiving unit to obtain the time information from the communication signal inputted to the antenna whose gain characteristics have been changed.