A capsule medical device configured to be introduced into a subject to acquire information about the subject is provided. The capsule medical device includes: a capsule-shaped casing including: a first casing including a hemispherical portion and a cylindrical portion； and a second casing that is a cylindrical casing where an opening edge portion having an opening is positioned at one end, the cylindrical portion of the first casing being fitted on an outer peripheral surface of the second casing on a side of the opening to incorporate an information acquisition member for acquiring information about the subject； and a positioning member including: a first abutment surface configured to abut on an end surface of the second casing on the side of the opening； and a second abutment surface configured to abut on the information acquisition member.
