Abstract: An electric typewriter having a prevention mechanism for preventing printing errors caused by a depression of a few keys in very rapid succession. The prevention mechanism includes a lock member for locking a clutch, which is interposed between a drive motor and a printing mechanism, in a disengaged condition. The lock member is normally held in a non-operational position for allowing the clutch to be engaged, and is moved in response to a special operation of a sensing member to an operational position for keeping the clutch in a disengaged condition. The sensing member is so disposed as to be moved in a distinct way different from the normal operation mode when a few keys have been depressed in very rapid succession.