A capturing device (1, 4, 6) comprising: an optical receiving means for receiving a beam from outside as a reception beam; a reception beam capturing means (16, 17, 18) for performing capturing operation which introduces the reception beam to the optical receiving means; an optical transmitting means for generating a transmission beam to transmit to outside; a transmission beam scanning means (11, 12, 21) for performing scanning operation of the transmission beams; and an optical circulator in which a same terminal is used for incidence of the reception beam and exit of the transmission beam, wherein the transmission beam scanning means (11, 12, 21) comprises: a coarse scanning means for performing the scanning operation by moving the transmission beam at a predetermined angle; and a fine scanning means (12, 21) for performing the scanning operation by moving the transmission beam at an angle narrower than an angle moving for use in the coarse scanning means, wherein the coarse scanning means is further configured to scan the transmission beam in accordance with a predetermined scanning path which is an approximately spiral path from a center cluster to an outside cluster in a plurality of overlapped clusters, and the fine scanning means (12, 21) is further configured to subsequently and respectively scan for each of the clusters on the spiral path from the center cluster to an outside cluster the transmission beam in accordance with a predetermined scanning path which is an overlapped spiral path from a center of the cluster to the outside of the cluster. an optical receiving means for receiving a beam from outside as a reception beam; a reception beam capturing means (16, 17, 18) for performing capturing operation which introduces the reception beam to the optical receiving means; an optical transmitting means for generating a transmission beam to transmit to outside; a transmission beam scanning means (11, 12, 21) for performing scanning operation of the transmission beams; and an optical circulator in which a same terminal is used for incidence of the reception beam and exit of the transmission beam, wherein the transmission beam scanning means (11, 12, 21) comprises: a coarse scanning means for performing the scanning operation by moving the transmission beam at a predetermined angle; and a fine scanning means (12, 21) for performing the scanning operation by moving the transmission beam at an angle narrower than an angle moving for use in the coarse scanning means, wherein the coarse scanning means is further configured to scan the transmission beam in accordance with a predetermined scanning path which is an approximately spiral path from a center cluster to an outside cluster in a plurality of overlapped clusters, and the fine scanning means (12, 21) is further configured to subsequently and respectively scan for each of the clusters on the spiral path from the center cluster to an outside cluster the transmission beam in accordance with a predetermined scanning path which is an overlapped spiral path from a center of the cluster to the outside of the cluster. a coarse scanning means for performing the scanning operation by moving the transmission beam at a predetermined angle; and a fine scanning means (12, 21) for performing the scanning operation by moving the transmission beam at an angle narrower than an angle moving for use in the coarse scanning means, wherein the coarse scanning means is further configured to scan the transmission beam in accordance with a predetermined scanning path which is an approximately spiral path from a center cluster to an outside cluster in a plurality of overlapped clusters, and the fine scanning means (12, 21) is further configured to subsequently and respectively scan for each of the clusters on the spiral path from the center cluster to an outside cluster the transmission beam in accordance with a predetermined scanning path which is an overlapped spiral path from a center of the cluster to the outside of the cluster.