An antenna apparatus configured to acquire information from a body-insertable apparatus that is configured to be inserted into a subject to move inside the subject, the antenna apparatus comprising: an antenna that includes one sheet in which a first positioning hole is formed; and an antenna holder that includes a container portion which is configured to hold the antenna at a predetermined position and in a predetermined orientation and in which a second positioning hole is formed at a position corresponding to the first positioning hole when the antenna is held, the antenna holder being configured to be attached to a predetermined position of the subject using the first and second positioning holes (49, 73) as an index when the antenna is held, wherein the antenna further includes a cable which extends from the sheet, the sheet has an upper side and a bottom side that are parallel to an extension direction of the cable, and a base end portion of the cable is disposed at a position that is deviated from an intermediate line of the upper and bottom sides of the sheet and is closer to the upper side, wherein the container portion of the antenna holder has such a pouch shape that the antenna can be inserted and has an opening that can be opened and closed, wherein plural receiving antennas (41 to 48) are fixed on the sheet, wires connected to the respective receiving antennas (41 to 48) are bundled in the cable, the opening is provided on the entire upper side of the container portion and in a partial side down a position of the cable when the antenna is held in the container portion in such a way that the bottom side of the sheet is positioned at a bottom of the container portion, the base end portion of the cable is positioned at an end portion of the opening and the first positioning hole is aligned with the second positioning hole when the antenna is held in the container portion in such a way that the bottom side of the sheet is positioned at the bottom of the container portion, and the base end portion of the cable is caught at the end portion of the opening and the first positioning hole is not aligned with the second positioning hole when the antenna is held in the container portion in such a way that the upper side of the sheet is oriented to the bottom of the container portion. an antenna that includes one sheet in which a first positioning hole is formed; and an antenna holder that includes a container portion which is configured to hold the antenna at a predetermined position and in a predetermined orientation and in which a second positioning hole is formed at a position corresponding to the first positioning hole when the antenna is held, the antenna holder being configured to be attached to a predetermined position of the subject using the first and second positioning holes (49, 73) as an index when the antenna is held, wherein the antenna further includes a cable which extends from the sheet, the sheet has an upper side and a bottom side that are parallel to an extension direction of the cable, and a base end portion of the cable is disposed at a position that is deviated from an intermediate line of the upper and bottom sides of the sheet and is closer to the upper side, wherein the container portion of the antenna holder has such a pouch shape that the antenna can be inserted and has an opening that can be opened and closed, wherein plural receiving antennas (41 to 48) are fixed on the sheet, wires connected to the respective receiving antennas (41 to 48) are bundled in the cable, the opening is provided on the entire upper side of the container portion and in a partial side down a position of the cable when the antenna is held in the container portion in such a way that the bottom side of the sheet is positioned at a bottom of the container portion, the base end portion of the cable is positioned at an end portion of the opening and the first positioning hole is aligned with the second positioning hole when the antenna is held in the container portion in such a way that the bottom side of the sheet is positioned at the bottom of the container portion, and the base end portion of the cable is caught at the end portion of the opening and the first positioning hole is not aligned with the second positioning hole when the antenna is held in the container portion in such a way that the upper side of the sheet is oriented to the bottom of the container portion.