PURPOSE: To provide an antenna for measuring polarize plane which can be used over a wide polarized plane measuring frequency band and can cover a wide area.

CONSTITUTION: An antenna 1 for measuring polarized plane is constituted by orthogonally combining two dipole antennas having the same characteristics rotationally symmetrically with respect to their feeding parts. The elements 10a-10d of each dipole antenna are constituted of platy conductors and at least the front end sections of the elements 10a-10d are formed to circular-arcuate shapes. In addition, feeding ports peculiar to dipole antennas are formed at base end sections of the elements 10a-10d and the flat surfaces of the elements 10a-10d are positioned perpendicularly or in parallel to the orthogonal surfaces of the antennas. The output of each dipole antenna is sent to a polarized plane leading-out means in the succeeding stage through a balun circuit 11.