A cover glass for a pen input device, said cover glass being characterized in that: the haze value is less than 1%; the Martens hardness is in the range of 2,000 N/mm2 to 4,000 N/mm2; when a moving member incurring a load of 150 gf (1.47 N) is moved in one direction with a speed of 10 mm/sec on the surface of the cover glass at room temperature, the coefficient of dynamic friction ([mu]k) is 0.14 - 0.50 in a region where the relationship between the dynamic friction force (Fk) (N) and time is approximated by a straight line, and the standard deviation ([sigma]) (N) of the dynamic friction force (Fk) (N) is 0.03 or less; and the moving member is a pen having a polyacetal resin pen tip with a Rockwell hardness of M90, with the pen tip having a radius of curvature of 700 [mu]m.