Method of manufacturing endoscope and endoscope

A method of manufacturing an endoscope provided with an insertion portion configured to be inserted into a subject, the insertion portion having a distal end provided with a sensor, the insertion portion having a cylindrical channel and a signal cable inserted therein, the signal cable being configured to be electrically connected to the sensor, the method comprising:

• dividing a plurality of signal lines to transmit a signal acquired by the sensor into a plurality of bundle portions;
• notching a part of a tube having heat shrinkability and an insulation property the notching excluding a portion of the tube in a circumferential direction of the tube to form one or more notches;
• cutting at least one end portion of the tube in a state where the tube is folded about each of the one or more notches to produce a first heat-shrinkable tube having a plurality of cylindrical portions, the plurality of cylindrical portions having end portions aligned in a longitudinal direction of the plurality of cylindrical portions;
• inserting the divided bundle portions into the plurality of cylindrical portions of the first heat-shrinkable tube, respectively;
• inserting the signal lines into a second heat-shrinkable tube, different from the first heat-shrinkable tube, the second heat-shrinkable tube having heat shrinkability and an insulation property;
• heating at least an overlapping portion of the first and second heat-shrinkable tubes in a state where the first and second heat-shrinkable tubes partially overlap each other to cause heat shrinkage of at least the overlapping portion;
• inserting the signal cable and the channel into a tubular portion having a tubular shape into which the signal cable and the channel are insertable;
• and
• connecting the tubular portion to a distal end housing provided at a distal end of the insertion portion, the distal end housing being configured to hold the sensor to form the distal end of the insertion portion.