A portable pen pointing device and a processing system with pen pointing device which can be easily used. The portable pen pointing device includes a memory for storing user's specific penmanship/handwriting information and a pen interface unit for supplying the user's specific penmanship/handwriting information to a processor body of the processing system. The processor body interprets a writing sample on the basis of the user's specific penmanship/handwriting information supplied from the portable pen pointing device through the pen interface unit thereof. With this construction, there is no need to read information from a storage medium such as a flexible disk in which a user's specific dictionary for penmanship/handwriting interpretation is written. Also, an operation of establishing a certain writing environment becomes unnecessary or easy.