Shaft (12) by the frame catheter (10A) includes a small diameter portion which constitutes the distal end side (24), and the small-diameter portion (24) large-diameter portion provided at the base end side than (26), and a tapered portion (28) provided between the small diameter portion (24) and the large diameter portion (26). Tapered portion (28) is flexible constructed than the large-diameter portion (26). The large-diameter portion (26) has a first large diameter section (38), and a second large diameter portion (39) provided between the tapered section (28) a first large diameter section (38) . The second large diameter section (39), which has a smaller outer diameter than the outer diameter of the outer diameter and the first large-diameter portion of the proximal end of the tapered portion (28) (38), a first large diameter section (38) flexibly configured thanカテーテル(10A)のシャフト(12)は、先端側を構成する細径部(24)と、細径部(24)よりも基端側に設けられた太径部(26)と、細径部(24)と太径部(26)との間に設けられたテーパ部(28)とを有する。テーパ部(28)は、太径部(26)よりも柔軟に構成される。太径部(26)は、第1太径部(38)と、テーパ部(28)と第1太径部(38)との間に設けられた第2太径部(39)とを有する。第2太径部(39)は、テーパ部(28)の基端の外径及び第1太径部(38)の外径よりも小さい外径を有するとともに、第1太径部(38)よりも柔軟に構成される。
