A lever-type connector comprising: a housing having a front, a rear, a left side and a right side and having contact accommodating holes extending in a front-to-rear direction from the front to the rear of the housing; a lever having a pair of side plates and a connection portion for connecting one end of each of the side plates with each other and capable of rotating in a left-to-right direction from the left side to the right side, with respect to the housing with the other end of each of the side plates defining a center of rotation; a wire cover attached at a rear surface side of the housing and for accommodating electrical wires extending from contacts accommodated in the contact accommodating holes; mating with a mating connector being released by rotating the lever to the left side in the left-to-right direction, the mating with the mating connector being completed by rotating the lever to the right side in the left-to-right direction to locate the lever at a mating completion position; lock pieces arranged at the connection portion; and a lock member arranged at a rear surface of the wire cover and for preventing the lever from rotating to said left side in the left-to-right direction by locking the lock pieces of the lever located at the mating completion position; characterised by: a release portion arranged at the connection portion and for releasing locking of the lock pieces locked by the lock member; wherein the lock member has a first plate spring portion extending from the wire cover to the right side in the left-to-right direction, and locked portions arranged at an end portion of the first plate spring portion and for locking the lock pieces, respectively; wherein the release portion has a second plate spring portion extending from the connection portion to the right side in the left-to-right direction, and a releasing projection portion extending outwards from an end portion of the second plate spring portion; and wherein the end portion of the second plate spring portion pushes inwards the end portion of the first plate spring portion, by pushing the releasing projection portion inwards, so that the lock pieces locked by the locked portions are released from the locked portions. a housing having a front, a rear, a left side and a right side and having contact accommodating holes extending in a front-to-rear direction from the front to the rear of the housing; a lever having a pair of side plates and a connection portion for connecting one end of each of the side plates with each other and capable of rotating in a left-to-right direction from the left side to the right side, with respect to the housing with the other end of each of the side plates defining a center of rotation; a wire cover attached at a rear surface side of the housing and for accommodating electrical wires extending from contacts accommodated in the contact accommodating holes; mating with a mating connector being released by rotating the lever to the left side in the left-to-right direction, the mating with the mating connector being completed by rotating the lever to the right side in the left-to-right direction to locate the lever at a mating completion position; lock pieces arranged at the connection portion; and a lock member arranged at a rear surface of the wire cover and for preventing the lever from rotating to said left side in the left-to-right direction by locking the lock pieces of the lever located at the mating completion position; characterised by: a release portion arranged at the connection portion and for releasing locking of the lock pieces locked by the lock member; wherein the lock member has a first plate spring portion extending from the wire cover to the right side in the left-to-right direction, and locked portions arranged at an end portion of the first plate spring portion and for locking the lock pieces, respectively; wherein the release portion has a second plate spring portion extending from the connection portion to the right side in the left-to-right direction, and a releasing projection portion extending outwards from an end portion of the second plate spring portion; and wherein the end portion of the second plate spring portion pushes inwards the end portion of the first plate spring portion, by pushing the releasing projection portion inwards, so that the lock pieces locked by the locked portions are released from the locked portions. a release portion arranged at the connection portion and for releasing locking of the lock pieces locked by the lock member; wherein the lock member has a first plate spring portion extending from the wire cover to the right side in the left-to-right direction, and locked portions arranged at an end portion of the first plate spring portion and for locking the lock pieces, respectively; wherein the release portion has a second plate spring portion extending from the connection portion to the right side in the left-to-right direction, and a releasing projection portion extending outwards from an end portion of the second plate spring portion; and wherein the end portion of the second plate spring portion pushes inwards the end portion of the first plate spring portion, by pushing the releasing projection portion inwards, so that the lock pieces locked by the locked portions are released from the locked portions.