Abstract: Provided is to a pen-type optical indexing apparatus and a method for controlling the same. The apparatus is a handheld device conveniently provided for a user to manipulate. Housing of the apparatus has an opening in the end, and the opening is a passage allowing emitting and receiving lights. The apparatus essentially includes a control unit for integrating the internal signals, a control interface unit provided for manipulating the apparatus to generate control signals, and an integrated circuit which packages a light-source module and a sensing module of the apparatus. The sensing module includes a sensor array composed of multiple sensing cells arranged in an array, and is used to sense the incident lights reflected by an external object. The apparatus includes a communication unit and a power management unit. One of operational modes including cursor-indicating mode, handwriting mode and touching mode can be activated while initiating the apparatus.