Attachment device and attachment method of information acquisition device

An attachment device that is capable of forming a first through hole in an outer peripheral surface of a pipe using a drilling machine and attaches an information acquisition device to acquire information regarding the pipe through the first through hole, the attachment device comprising:

• a pipe attachment portion attachable to the pipe and including an opening communicating with the first through hole;
• a valve portion attached so as to communicate with the opening;
• a first valve connection portion connecting the opening and the valve portion;
• an attachment portion to which the drilling machine or the information acquisition device can be attached;
• and
• a second valve connection portion connecting the valve portion and the drilling machine or the information acquisition device;
• wherein
• the second valve connection portion includes:
• a first main body that is tubular and insertable into a second through hole in the valve portion and the drilling machine or the information acquisition device;
• and
• a first elastic portion on an outer peripheral surface of the first main body to seal between the outer peripheral surface of the first main body and an inner peripheral surface of the second through hole;
• and
• the first main body is connectable to the drilling machine or the information acquisition device by being inserted into the second through hole so as to be pushed against a frictional force of the first elastic portion.