A free-space optical communication apparatus includes a storage unit which
stores angle-setting information for the mirror for communicating with
each of the plurality of other apparatuses, a mirror driving unit which
drives the mirror to an angle corresponding to the stored angle-setting
information, an optical detecting unit which, on one occasion for
communicating with a specified communication apparatus among the
plurality of other apparatuses, detects the incident state of an optical
beam sent from the specified apparatus, and a control unit which, based
on the detected incident state of the optical beam, determines
angle-correcting information for correcting the stored angle-setting
information for the specified apparatus, and which, on the next occasion
for communicating with the specified apparatus, uses the mirror driving
unit to drive the mirror to an angle corresponding to the angle-setting
information corrected by the angle-correcting information.