A catheter (1) includes a first opening portion (300) that is positioned at a distal end a first curved portion (4) that is positioned at a proximal end side of the first opening portion (300), and is curved in a first direction a second curved portion (5) that is positioned at a proximal end side of the first curved portion (4), and is curved in a second direction an intermediate portion (6) that is provided between the first curved portion (4) and the second curved portion (5) and a second opening portion (7) that is formed in the intermediate portion (6). In transverse sectional view of the intermediate portion (6), the first direction and the second direction are directions directed towards the same side. In addition, in transverse sectional view of the intermediate portion (6), the second opening portion (7) opens in a direction directed towards a side that is opposite to the side towards which the first and second directions are directed.
