An antenna is realized by a simple mechanism without use of a dedicated antenna element. An antenna includes a first conductor 2b (2d) that has a first line length from a start point 4 to a folded point 3; and a second conductor 2b (2d) that has a second line length in a direction from the folded point 3 to the start point 4 and is electrically connected to the first conductor at the folded point 3. A first received signal with a first frequency is received with a first antenna length including both the first line length and the second line length. A second received signal with a second frequency is received with a second antenna length including only one of the first line length and the second line length.