A front-end circuit comprising: an RFIC; a transmission and reception antenna; N duplexers (93-1, 93-2,..., 93-N) in between the RFIC and the transmission and reception antenna, an i-th duplexer of the N duplexers (93-1, 93-2,..., 93-N) being for use in transmission and reception of signals in an i-th frequency band of predetermined first to N-th frequency bands, where N is a predetermined integer greater than or equal to 2 and i denotes an integer satisfying 1≤i≤N; a control unit adapted to receive a control signal from the RFIC, characterized in that the front-end circuit comprises: N variable impedance adjustment circuits (17-1, 17-2,..., 17-N), an i-th variable impedance adjustment circuit of the N variable impedance adjustment circuits (17-1, 17-2,..., 17-N) being connected to a common terminal of the i-th duplexer; and a switch connected to the transmission and reception antenna and adapted to select any two of the N variable impedance adjustment circuits (17-1, 17-2,..., 17-N), wherein the control unit is adapted to execute switching operations of the N variable impedance adjustment circuits (17-1,17-2,...,17-N) and the switch in accordance with control information indicated by the control signal; and the control signal indicates to, when a p-th frequency band and a q-th frequency band of the predetermined first to N-th frequency bands are selected, where p denotes an integer satisfying 1≤p≤N, q denotes an integer satisfying 1≤q≤N and p≠q: control the switch to select two variable impedance adjustment circuits corresponding to the p-th frequency band and the q-th frequency band respectively; control a selected variable impedance adjustment circuit corresponding to the p-th frequency band to increase input impedance in the q-th frequency band as viewed from the transmission and reception antenna side; and control a selected variable impedance adjustment circuit corresponding to the q-th frequency band to increase input impedance in the p-th frequency band as viewed from the transmission and reception antenna side. an RFIC; a transmission and reception antenna; N duplexers (93-1, 93-2,..., 93-N) in between the RFIC and the transmission and reception antenna, an i-th duplexer of the N duplexers (93-1, 93-2,..., 93-N) being for use in transmission and reception of signals in an i-th frequency band of predetermined first to N-th frequency bands, where N is a predetermined integer greater than or equal to 2 and i denotes an integer satisfying 1≤i≤N; a control unit adapted to receive a control signal from the RFIC, characterized in that the front-end circuit comprises: N variable impedance adjustment circuits (17-1, 17-2,..., 17-N), an i-th variable impedance adjustment circuit of the N variable impedance adjustment circuits (17-1, 17-2,..., 17-N) being connected to a common terminal of the i-th duplexer; and a switch connected to the transmission and reception antenna and adapted to select any two of the N variable impedance adjustment circuits (17-1, 17-2,..., 17-N), wherein N variable impedance adjustment circuits (17-1, 17-2,..., 17-N), an i-th variable impedance adjustment circuit of the N variable impedance adjustment circuits (17-1, 17-2,..., 17-N) being connected to a common terminal of the i-th duplexer; and a switch connected to the transmission and reception antenna and adapted to select any two of the N variable impedance adjustment circuits (17-1, 17-2,..., 17-N), the control unit is adapted to execute switching operations of the N variable impedance adjustment circuits (17-1,17-2,...,17-N) and the switch in accordance with control information indicated by the control signal; and the control signal indicates to, when a p-th frequency band and a q-th frequency band of the predetermined first to N-th frequency bands are selected, where p denotes an integer satisfying 1≤p≤N, q denotes an integer satisfying 1≤q≤N and p≠q: control the switch to select two variable impedance adjustment circuits corresponding to the p-th frequency band and the q-th frequency band respectively; control a selected variable impedance adjustment circuit corresponding to the p-th frequency band to increase input impedance in the q-th frequency band as viewed from the transmission and reception antenna side; and control a selected variable impedance adjustment circuit corresponding to the q-th frequency band to increase input impedance in the p-th frequency band as viewed from the transmission and reception antenna side. control the switch to select two variable impedance adjustment circuits corresponding to the p-th frequency band and the q-th frequency band respectively; control a selected variable impedance adjustment circuit corresponding to the p-th frequency band to increase input impedance in the q-th frequency band as viewed from the transmission and reception antenna side; and control a selected variable impedance adjustment circuit corresponding to the q-th frequency band to increase input impedance in the p-th frequency band as viewed from the transmission and reception antenna side.