A steerable catheter includes a flexible tube having a distal end and a proximal end. The tube includes a first tube section (sheath body section) the flexibility of which does not substantially change even upon receiving compression force in the axial direction; and a second tube section (deflection section) joined so as to be continuous with the distal end of the first tube section and constituted by a porous tube becoming hard upon being compressed according to the degree of the compression force acting in the axial direction and returning to being soft when the compression force is released. The tube includes operation means (wires) for releasably exerting a compression force compressing the second tube section in the axial direction and a deflection force deflecting the second tube section. According to some embodiments, both operability and insertability of the steerable catheter can be improved.