A medical tube of the invention includes: a tube main body 13 through which a conduit 13a, through which an insertion portion 3 of a cholangioscope 1 is insertable, is pierced from a distal end to a rear end a side hole 13b that is formed between the distal end and the rear end of the tube main body 13 and causes an outer circumferential side of the insertion portion 3 and the conduit 13a to communicate with each other and a hardness changing portion 14 that can change the hardness of at least a part of the tube main body 13 including the side hole 13b according to operation by an operator.
