An antenna apparatus for a portable telephone which is capable of having a better gain characteristic and also capable of achieving a better circularly polarized characteristic over a wide range is provided. This antenna apparatus is comprised of: a first cylinder 4 provided in such a manner that the first cylinder is uprighted on an upper portion 1 of a housing of the portable telephone; 4-element dipole array antennas 4a to 4d connected to a transmitter/receiver circuit built in the housing via a feeding line path, and arranged on the surface of the first cylinder in an equiinterval in such a manner that the 4-element dipole array antennas have inclined angles with respect to a central axis of the first cylinder, an element length of the 4-element dipole array antennas being equal to an approximately 1/2 electromagnetic wavelength; a second cylinder 5 having a diameter smaller than an inner diameter of the first cylinder, and arranged in such a manner that the second cylinder can be stored into the first cylinder, and when the second cylinder is drawn from the first cylinder, the second cylinder is uprighted in the vicinity of an upper space of the first cylinder in a coaxial manner; and 4-element line-shaped conductors 5a to 5d arranged on the surface of the second cylinder in an equiinterval in such a manner that the 4-element line-shaped conductors have inclined angles with respect to a central axis of the second cylinder.