A terminal device includes a first memory that stores a position of each of antennas included in a main body of a terminal device for each of holding manners for the main body of the terminal device, a second memory, a processor coupled to the second memory, configured to detect a holding manner for the main body of the terminal device including the antennas, detect a shape indicating a shadow of an object pointing to a surface of the terminal device, identify a holding hand that holds the main body of the terminal device, based on the detected shape, and switch an antenna which overlaps with the holding hand to another antenna based on the identified holding hand and the position of each antenna stored in the first memory, the antenna corresponding to the detected holding manner.