PROBLEM TO BE SOLVED: To provide an antenna which is small in height and size, which is capable of responding to frequency bands equivalent to those of a conventional antenna, and which provides high design flexibility in an antenna mounting part.SOLUTION: The antenna comprises an antenna element portion 2 for transmitting/receiving an electromagnetic wave signal, and a ground conductor 3 to be grounded. The antennal element portion 2 is provided between a coaxial cable 8 having a central conductor 4 and an external conductor 6, and one end of one of the central conductor 4 and the external conductor 6 and the ground conductor 3. The antenna element portion 2 further comprises: a feeding portion 10 to be connected to a power feeding system; a short-circuit portion 11 that electrically connects one end of the other one of the central conductor 4 and the external conductor 4, and the ground conductor 3; and a conductor connecting portion 12 that electrically connects the other end of the central conductor 4 and the other end of the external conductor 6. The coaxial cable 8 has an overall length that is equal to or less than a half of a wavelength corresponding to the minimum series resonant frequency. The distance between the central conductor 4 and the external conductor 6 is equal to or less than 1/100 of a wavelength corresponding to the minimum frequency among frequencies at which the antenna operates.