A medical tube (30) includes: a main body (31) in which a distal portion of a tubular proximal separable piece (33) is detachably connected to a proximal portion of a tubular distal separable piece (32) and a state maintaining mechanism (34) for maintaining a connected state of the distal separable piece (32) and the proximal separable piece (33). In addition, the main body (31) is inserted into a body starting from the distal separable piece (32) side, and is disposed inside the body in a state in which a distal end and a proximal end thereof are exposed outside of the body. Besides, the state maintaining mechanism (34) includes a string (341) which is disposed inside the main body (31) and interlocks the distal separable piece (32) and the proximal separable piece (33), and the connected state can be released by cutting the string (341).