An electronic apparatus has a slot for accommodating a stylus. The electronic apparatus includes a locking module, an input interface and a control circuit. The locking module is disposed adjacent to the slot. The locking module is configured to have a locked mode and an unlocked mode. Under the locked mode, the locking module is configured to lock the stylus in the slot. The input interface is configured to obtain authentication information. The control circuit is configured to verify the authentication information obtained by the input interface. When the authentication information is verified, the control circuit switches the locking module from the locked mode into the unlocked mode.