PURPOSE: To constitute the marine satellite communication system not requiring the antenna stabilizing stand and tracking unit of high accuracy, by using the small sized antenna with non-directivity over the range of angle more than a given amount of angle of elevation without the sensitivity toward horizontal direction.

CONSTITUTION: The small sized non-directivity antenna 6 is constituted by arranging the radiation element 6 and reflection element orthogonal each other so that the pattern 9 radiating electromagnetic waves toward the sky can be obtained. Thus, even if the ship 8 is pitched at the range of angle of a given elevation, electromagnetic waves can be transmitted and received to the communication satellite 10. Further, since the radiation pattern 9 has no sensitivity horizontally, even under the condition of the ship 8 pitched, it is not subjected to the effect of useless radiation such as reflection on sea surface, enabling stable communication. The length of the element 6 is about 1/2 wave length and the element is very small in size and light in weight, and cable loss can be eliminated with the transmission and reception unit 7 imcorparated, and the space on board can effectively be used.