PURPOSE: To facilitate the observation inserting an image guide, a light guide, an expansion use fluid leading-in tube, a guide tube for a direction changing wire, etc., in a free state, into a thin diameter tube body to raise the flexibility.

CONSTITUTION: In a thin diameter tube body 2, an image guide 3 provided with an objective lens 5 on the tip, a light guide 4 whose tip is fixed to the lens 5, a leading-in tube 25 for leading in a fluid for expanding a balloon 24, a guide tube 16 for a wire 21 for changing a direction of the tube body 2, etc. are inserted in a free state. Accordingly, the flexibility of this fiber scope becomes higher than the case when these parts have been formed as one body and inserted, and the observation is executed easily.