An electronic endoscope comprising: an insertion portion which includes an insulative distal end hard portion main body at a distal end thereof and which is configured to be inserted into a hole; an operation portion which is provided at a proximal end portion of the insertion portion and which includes a connector connecting portion electrically connected to a ground portion; an observation optical system which includes an optical element and a frame member having conductive properties and holding the optical element, and which is extended from the distal end of the insertion portion toward the operation portion; and a ground metal member formed as a cylindrical connection tube which is provided between the distal end hard portion main body of the insertion portion and the operation portion, which forms a structure of the insertion portion, and which is electrically conductive with respect to the ground portion through the connector connecting portion; the ground metal member including a conductive connecting portion which allows the frame member of the observation optical system to become electrically conductive with respect to the ground metal member, wherein the frame member is arranged on the inner side of the ground metal member, wherein the conductive connecting portion includes a contact portion with conductive properties which is formed on a part of the ground metal member and protrudes toward the frame member to abut on the frame member; characterized by further comprising a U-like or crescent-like slit formed in the ground metal member, wherein the contact portion is formed by the slit and has a tongue-like shape and is inwardly folded toward the inner side along the radial direction of the ground metal member, and wherein the contact portion is brought into contact with the frame member to achieve the electrical conduction between the frame member and the ground metal member. an insertion portion which includes an insulative distal end hard portion main body at a distal end thereof and which is configured to be inserted into a hole; an operation portion which is provided at a proximal end portion of the insertion portion and which includes a connector connecting portion electrically connected to a ground portion; an observation optical system which includes an optical element and a frame member having conductive properties and holding the optical element, and which is extended from the distal end of the insertion portion toward the operation portion; and a ground metal member formed as a cylindrical connection tube which is provided between the distal end hard portion main body of the insertion portion and the operation portion, which forms a structure of the insertion portion, and which is electrically conductive with respect to the ground portion through the connector connecting portion; the ground metal member including a conductive connecting portion which allows the frame member of the observation optical system to become electrically conductive with respect to the ground metal member, wherein the frame member is arranged on the inner side of the ground metal member, wherein the conductive connecting portion includes a contact portion with conductive properties which is formed on a part of the ground metal member and protrudes toward the frame member to abut on the frame member; characterized by further comprising a U-like or crescent-like slit formed in the ground metal member, wherein the contact portion is formed by the slit and has a tongue-like shape and is inwardly folded toward the inner side along the radial direction of the ground metal member, and wherein the contact portion is brought into contact with the frame member to achieve the electrical conduction between the frame member and the ground metal member.