A catheter kit includes a catheter having an optical fiber, and a catheter accommodating tool which accommodates the catheter. The catheter accommodating tool has a tubular hoop, and a position adjustment mechanism provided at the hoop. The hoop has a hoop tip end portion at which a catheter tip end portion, from which laser light transmitted through the optical fiber is emitted, is disposed, and a hoop base end portion which is opposite to the hoop tip end portion. The position adjustment mechanism is provided at the hoop base end portion and changes a position of the catheter tip end portion with respect to the hoop tip end portion.