A knock type sharp pencil provided in its outer cylinder with a core holding mechanism composed of an inner cylinder coaxially arranged in the outer cylinder, a lead chuck inserted in the inner cylinder and including a chuck portion projecting out of the front end of the inner cylinder, a chuck ring inserted between a flange portion of the inner cylinder and the chuck portion of the lead chuck, a core case provided at its rear end with a knock portion and connected to the rear end of the lead chuck, and a spring means arranged in the inner cylinder and inserted between the flange portion of the inner cylinder and the front end portion of the core case, the spring means urging the core case backwardly.