An indwelling medical device having a marker portion that can be easily identified after being implanted in the body without hindering miniaturization of the medical device. A main body 100 having a liquid reservoir portion 50 for storing a chemical solution, an engaging portion 23 (23a, 23b, 23c) formed in the main body 100, and a marker portion 250 engaged with the engaging portion 23, The indwelling medical apparatus 1 is comprised by these. In the indwelling medical device 1, the sign unit 250 indicates a sign body 251 that is at least one of a character, a mark, or a graphic related to the indwelling medical device. And the label marker part 250 shows this label marker body 251 by the transmittance permeability of X-ray differing with the label marker body 251 and its surrounding area. [Selection] Figure 4【課題】医療機器の小型化を妨げることがなく、体内に埋め込まれた後に容易に識別できる標識部を有する留置型医療機器を提供する。【解決手段】薬液を貯留する液溜り部５０を有する本体１００と、本体１００に形成された係合部２３（２３ａ、２３ｂ、２３ｃ）と、係合部２３に係合される標識部２５０と、によって、留置型医療機器１を構成する。留置型医療機器１では、標識部２５０は、留置型医療機器に関する文字、マークまたは図形の少なくとも一つである標識体２５１を示す。そして標識部２５０は、Ｘ線の透過率が標識体２５１とその周囲領域とで異なることによって該標識体２５１を示す。【選択図】図４
