The invention relates to a pencil sharpener, comprising a clamping chuck (1) that feeds a pencil rotationally fixed therein to a rotating milling device. The clamping chuck (1) comprises a plurality of locating tongues (8) pointing almost radially towards a clamp chuck axis (4) to fix the pencil, said tongues being connected to a holding frame(7) surrounding the clamp chuck axis (4) in such a way that they cannot rotate. When the holding frame (7) is pivoted around the clamp chuck axis (4), the locating tongues (8) are bent in the form of a unilaterally tensed bar spring and interacting with stops (15) of a clamp chuck housing (2, 3). The radial inner locating ends (10) of the locating tongues (8) are pivoted outwards to open the clamp chuck (1). The restoring tension of the bent locating tongues (8) is simultaneously used as closing tension for the clamp chuck (1).