Abstract: A flexible endoscope of the present invention includes a catheter portion and a connection plug. The catheter portion includes an image guide, a light guide, and a catheter tube that surrounds the image guide and the light guide in a longitudinal direction, and the connection plug includes a hollow cover that accommodates the proximal end of the catheter tube, a flexible tube that protrudes from the hollow cover and through which the catheter tube is passed, a first connection terminal that is connected to the light guide extending from the proximal end of the catheter tube, and a second connection terminal that is connected to the image guide extending from the proximal end of the catheter tube. The image guide and the light guide are slidable inside the catheter tube, and at least one of the image guide and the light guide is arranged curved inside the hollow cover of the connection plug.